Adrenocortical control of phenylethanolamine-N-methyl transferase and monoamine oxidase activity in the ground squirrel (Citellus citellus) during the summer.

Phenylethanolamine-N-methyl transferase (PNMT) and monoamine oxidase (MAO) activity was studied during the summer in the active male ground squirrel (Citellus citellus) treated with metopirone, adrenocorticotrophin (ACTH), or dexamethasone. Cortisol and corticosterone almost disappeared from the circulation 1 hr after treatment with metopirone (75 mg/animal); they were also lower than in the controls 24 hr later (P < 0.025). Metopirone treatment resulted in a slight increase in adrenal weight as well as a decrease in adrenal PNMT activity (P < 0.01). In the liver, heart, kidney, lung, brown fat, and hypothalamus MAO activity was higher in metopirone-treated animals than in the controls (P < 0.01). Treatment with ACTH (6 IU of depot preparation/animal) resulted in an increase in adrenal weight (P < 0.01) as well as in PNMT activity (P < 0.005). In corticotrophin- as well as in dexamethasone (1 mg/animal)-treated animals MAO activity in the liver, heart, kidney, lung, brown fat, and hypothalamus was lower than in the nontreated controls (for all the tissues except the lung P < 0.005; for the lung P < 0.05). The results suggest that the adrenal cortex participates in the control of PNMT and MAO activity in the ground squirrel during the summer by stimulating PNMT activity and depressing MAO activity.     

Annual cyclical changes in the monoamine oxidase (MAO) activity in the testis of the teleost, Channa punctatus (Bloch)

Correlative changes in the monoamine oxidase (MAO) activity were recorded biochemically in the testis of Channa punctatus during different phases of the annual reproductive cycle. MAO activity increased with increase in testicular weight and maturity and declined during the postspawning and resting phases. This suggests that MAO may play some role in the growth cycle of the testis. On the other hand, 5-hydroxytryptamine (5-HT) concentration was found to be high in the testis during the resting phase and was markedly reduced during the spawning phase. Thus, there seems to be an inverse relationship between MAO and 5-HT in the testis during its annual cycle.     

Effects of breeding conditions on neurochemical cholinergic and monoaminergic markers in aged rat brain

We investigated the effects of breeding conditions on neurochemical markers, muscarinic receptor (mAChR), beta-adrenoreceptor (beta-AdrR), imipramine binding sites (IMBS), choline acetyltransferase (ChAT), acetylcholinesterase (AChE) and monoamine oxidase (MAO) activity in aged rat brains. An increase of affinity (Kd) and the decrease in the number (Vmax) of mAChR were found in the individual aged rats. Concerning IMBS, Kd and Vmax values increased in the individual aged rats. However, no significant changes were observed in the beta-AdrR. The increases of ChAT and MAO activity were found in the aggregated aged rats to compare with in the individual aged rats, while AChE activity decreased in the aggregated aged rats. These changes were also particularly seen in the forebrain of aged rats. These results indicate that the functions of the central nervous system may be reduced in the individual aged rats to compare with in the aggregated aged rats under the breeding conditions.     

Differences in the clinicopathological features of pancreatic head carcinoma in dorsal and ventral pancreas: A single institution retrospective review

The embryonic development of the pancreas originates from dorsal and ventral anlagen, and the pancreatic cancer arising from dorsal or ventral pancreas may have different clinical pathology features. This study aims to explore whether there are differences in clinicopathological features and prognosis of pancreatic head carcinoma arising from dorsal or ventral pancreas.Between January 2014 and February 2018, 101 patients with resectable pancreatic head cancer who underwent pancreaticoduodenectomy in our institution were retrospectively reviewed. The patients were assigned into 2 groups according to tumor location on preoperative imaging materials (computed tomography/magnetic resonance imaging [CT/MRI]), and the clinicopathological features and prognosis were retrospectively analyzed in view of the embryonic development of the pancreas.Among these patients with pancreatic head cancer, 42 patients had tumors arising from dorsal pancreas (D group) and 59 patients had tumors arising from ventral pancreas (V group). The frequency of lymph node (LN) metastasis around the common hepatic artery (CHA) and hepatoduodenal ligament lymph nodes in the D group was higher than that in the V group (45.2% vs 10.2%, P = .001). And the rate of LN metastasis in the superior mesenteric artery (SMA) region in the V group is higher than that in the D group (32.2% vs 4.8%, P = .002). The D group was more likely to invade the common bile duct (78.6% vs 59.3%, P = .042) and duodenum (71.4% vs 44.1%, P = .006) than the V group. In addition, the survival outcome of V group was better than D group (median overall survival [OS], 15.37 months vs 10.53 months, P = .048, median DFS 9.73 months vs 5.93 months, P = .046).The clinicopathological features of pancreatic head carcinoma arising from dorsal or ventral pancreas are different, and the pancreatic head carcinoma arising from ventral pancreas has a better survival outcome.     

Involvement of pancreatic and bile ducts in autoimmune pancreatitis

AIM:To examine the involvement of the pancreatic andbile ducts in patients with autoimmune pancreatitis.METHODS:Clinical and cholangiopancreatographic find-ings of 28 patients with autoimmune pancreatitis wereevaluated.For the purposes of this study,the pancreaticduct system was divided into three portions:the ventralpancreatic duct;the head portion of the dorsal pancre-atic duct;and the body and tail of the dorsal pancreaticduct.RESULTS:Both the ventral and dorsal pancreatic ductswere involved in 24 patients,while in 4 patients only thedorsal pancreatic duct was involved.Marked stricture ofthe bile duct was detected in 20 patients and their initialsymptom was obstructive jaundice.Six patients showedmoderate stenosis to 30%-40% of the normal diameter,and the other two patients showed no stenosis of thebile duct.Although marked stricture of the bile duct wasdetected in 83%(20/24)of patients who showed nar-rowing of both the ventral and dorsal pancreatic ducts,itwas not observed in the 4 patients who showed involve-ment of the dorsal pancreatic duct alone(P=0.0034).     

Monoamine oxidase in rat ovary during the estrous cycle. A histochemical study by a new coupled peroxidatic oxidation method

A new coupled peroxidatic oxidation method for histochemical detection of monoamine oxidase (MAO) was applied to rat ovary. With this new method, fixed tissues could be used, and two forms of MAO could be identified by use of selective inhibitors. MAO activity was observed in the corpora lutea, interstitial gland cells, and blood vessels. In the corpora lutea, no activity was detected during the first estrous cycle, but strong activity was observed in the next two cycles. MAO in blood vessels showed characteristic changes of activity during the estrous cycle. The results suggest that MAO activity might possibly be involved in ovulation and progesterone metabolism in the ovary. Like other organs, rat ovary was found to contain two types of MAO; type A MAO was predominant in the corpora lutea. On the other hand, only one type of MAO, type B, was found in the blood vessels.     

Androgen metabolism in skin and skeletal muscle of the rainbow trout (Salmo gairdnerii) and in accessory sexual organs of the spur dogfish (Squalus acanthias).

The in vitro metabolism of testosterone, 4-androstene-3,17-dione (androstenedione) and dehydroepiandrosterone by skin and muscle from the rainbow trout (Salmo gairdnerii), and by skin and accessory sexual tissues from the spur dogfish (Squalus acanthias) was studied. In trout skin, testosterone was transformed mainly into 5α-dihydrotestosterone together with smaller amounts of 5α-androstane-3α, 17β-diol, androstenedione, 5α-androstane-3,17-dione and androsterone. Androstenedione was transformed mainly into 5α-androstane-3,17-dione with smaller amounts of testosterone, 5α-dihydrotestosterone, androsterone and 5α-androstane-3α,17β-diol. Dehydroepiandrosterone was transformed to 5-androstene-3β,17β-diol with trace quantities of androstenedione and 5α-androstane-3,17-dione. Unidentified polar nonconjugated metabolites and traces of steroid glucuronides were formed from the three substrates. The patterns of steroid metabolism were similar in dorsal and ventral skin, and in dorsal skin from male and female, adult and immature fish. Most of the 5α-reductase activity in the skin was in the dermis, only a small fraction of the total activity being in the epidermis. The trout muscle converted testosterone into 5α-dihydrotestosterone but in much lower yields than did skin.The skin, clasper, sperm sac and vas deferens of an adult male spur dogfish converted testosterone to 5α-dihydrotestosterone and androstenedione, though in much lower yields than did trout skin. Androstenedione was converted into testosterone, 5α-androstane-3, 17-dione and androsterone, while dehydroepiandrosterone was converted into 5-androstene-3β,17β-diol. No metabolism of testosterone was detected in the skeletal muscle of the dogfish.     

A Histopathological Study on the Etiology of Duodenal Diverticulum Related to the Fusion of the Pancreatic Anlage

In 18 of 27 cases a duodenal diverticulum, which usually occurs at "weak" spots in the bowel wall, penetrated the pancreas. Of these, 14 cases (77.8%) extended along the embryological fusion line of the ventral and dorsal components, which is considered to be the so-called "locus minoris resistantiae." In four cases the diverticulum penetrating the ventral pancreas was in close approximation to the locus minoris resistantiae.     

Maternal hypothyroxinemia disrupts neurotransmitter metabolic enzymes in developing brain.

Maternal thyroid status influences early brain development and, consequently, cognitive and motor function in humans and rats. The biochemical targets of maternal thyroid hormone (TH) action in fetal brain remain poorly defined. A partially thyroidectomized rat dam model was therefore used to investigate the influence of maternal hypothyroxinemia on the specific activities of cholinergic and monoaminergic neurotransmitter metabolic enzymes in the developing brain. Maternal hypothyroxinemia was associated with reduced monoamine oxidase (MAO) activity in fetal whole brain at 16 and 19 days gestation (dg). A similar trend was observed for choline acetyltransferase (ChAT) activity. In contrast, DOPA decarboxylase (DDC) activity was markedly elevated at 21 dg. Further study of these enzymes at 14 dg showed no differences between normal and experimental progeny - suggesting they become TH sensitive after this age. Tyrosine hydroxylase (TyrH) and acetylcholinesterase (AChE) activities were unaffected prenatally. During postnatal development, the activities of TyrH, MAO, DDC and, to a lesser extent, AChE were increased in a brain region- and age-specific manner in experimental progeny. The prenatal disturbances noted in this study may have wide-ranging consequences since they occur when neurotransmitters have putative neurotropic roles in brain development. Furthermore, the chronic disturbances in enzyme activity observed during postnatal life may affect neurotransmission, thereby contributing to the behavioural dysfunction seen in adult progeny of hypothyroxinemic dams.     

Modifications hypophysaires et thyroïdiennes chez le pleurodèle en milieu salin

In the pituitary gland of Pleurodeles kept in a saline solution (NaCl, 9 g/liter) for 15 days, ventral orangeophilic cells appear less active, dorsal erythrosinophilic cells enlarge, and the intermediate lobe seems less active than in freshwater animals. Caryometric data corroborate these findings. Published results on osmoregulation generally indicate that prolactin (PRL) secretion is reduced in a saline environment, an observation which may be correlated with the hypoactivity detected in the orangeophilic cells simultaneously labelled with an anti-ovine prolactin antibody. The localization of growth hormone (STH) and melanocorticotropic hormone secretion is in accordance with previous cytoimmunological data. The histological structure of the thyroid gland suggests an increased activity in saline solution which may facilitate osmotic adaptation.     

Functional identification of the hematopoietic stem cell niche in the ventral domain of the embryonic dorsal aorta

The first definitive/adult-type hematopoietic stem cells (HSCs) in the mouse aorta-gonad-mesonephros region emerge between embryonic days 10.5 and 11.5. The discovery of clusters of hematopoietic cells on the ventral luminal surface of the dorsal aorta in various vertebrate species has led to speculation that the floor of the dorsal aorta may play an essential role for the development of the definitive hematopoietic system. Here, we functionally show affiliation of definitive HSCs with the ventral floor of the dorsal aorta, whereas colony-forming hematopoietic activity is associated with both ventral and dorsal domains. We show that a rare population of PECAM1(high)CD45(+) cells, within which definitive HSCs reside, is predominantly localized to intraaortic clusters. Furthermore, using ex vivo culture analysis, we demonstrate that the ventral domain of the dorsal aorta has an exclusive functional capacity of inducing and expanding definitive HSCs.     

Acetylcholinesterase activity in the brain of alloxan diabetic albino rats: Presence of an inhibitor of this enzyme activity in the cerebral extract

Background and Aim:

Ischemic manifestations and cerebral dysfunction have been demonstrated in diabetes. However, the pathogenesis of diabetes-induced cerebral dysfunction still remains to be elucidated. Hence, the present study was initiated.

Materials and Methods:

Type-2 diabetes was induced in albino rats (280–300g) with alloxan monohydrate (40 mg/Kg i.v.,) and the cerebrum, cerebellum and medulla oblongata of the brain were used 48 h after alloxan injection for modulations in acetylcholinesterase (AChE, EC 3.1.1.7) activity.

Results:

AChE activity in the discrete regions of the brain of rats decreased significantly (P<0.01, 0.05 and 0.05 respectively) in diabetes. In vitro studies using cerebral extract from alloxan diabetic rats demonstrated significant (P<0.05) inhibition of AChE activity in the brain of normal animals. Feeding with Cichorium intybus (chicory) leaf extract (500 mg/Kg) for 10 days resulted in an increase in AChE activity.

Conclusion:

The impairment in the glycemic control is the basic mechanism causing inhibition of neuronal activity. Cerebral extract from alloxan diabetic rats significantly inhibited the brain AChE activity of normal animals, indicating the presence of an inhibiting factor in the cerebrum of diabetic rats. Cichorium intybus when fed for 10 days offered neuroprotection by stimulating AChE activity.     

Non-alcoholic fatty liver induces insulin resistance and metabolic disorders with development of brain damage and dysfunction

In the present study we investigated the effect of the non-alcoholic fatty liver disease (NAFLD) on the alterations in the activity of neurotransmitters catabolizing enzymes and energy catabolising enzymes, prooxidants, endogenous antioxidants and proinflammatory cytokines in brain tissue of NAFLD rats. Rats were intraperitonealy injected with CCl4 solution at a dose of (0.021?mole/Kg, 20?μL, body weight) three times weekly for four weeks. Acetylcholine esterase (AChE), monoamine oxidase (MAO), prooxidant/ antioxidants status, ATPase, lipid profile and glucose level were estimated spectrophotometrically while inflammatory markers; interleukin 6 and tumor necrosis factor alpha (IL6 and TNF-α) and insulin were assessed by ELISA technique. Our results showed that the induced NAFLD and insulin resistance (IR) were accompanied with hyperglycemia and hyperlipidemia and lowered brain glucose level with elevated ATPase activity, prooxidant status (TBARS level, xanthine oxidase and cytochrome 2E1 activities), and inflammatory markers. Through the induction period AChE activity was significantly increased compared to control in blood, liver and brain tissues. Also, MAO activity was significantly increased in both brain and liver tissue but decreased in serum compared with control. These biochemical data were supported with pathophysiological analysis that showed severe neurodegeneration, pyknosis acuolations and cavitations. These observations warrant the reassessment of the conventional concept that the NAFLD with IR progression may induce disturbances in activities of neurotransmitters catabolising enzymes and energy production accompanied with oxidative stress and metabolic disorders, acting as relative risk factors for brain dysfunction and damage with the development of age-associated neurodegenerative diseases such as Alzheimer's disease.     

Age-related changes of muscarinic cholinergic receptor subtypes in the striatum of Fisher 344 rats

Striatum expresses a cholinergic system involved in the regulation of its activity and changes in striatal cholinergic receptors may be related to cognitive impairment. This study has investigated muscarinic cholinergic M1-M5 receptor subtype expression in striatum of Fischer 344 rats aged 6 (young), 15 (adult) and 22 months (senescent) to assess the contribution of different muscarinic cholinergic receptor subtypes in age-related changes of striatal cholinergic neurotransmission. Western blot analysis revealed the expression of the M1-M5 muscarinic receptor subtytpes in the striatum of rats of the three age groups investigated. Both radioligand binding assay and light microscope autoradiography showed in young rats a M4>M1>M2>M3>M5 rank order of receptor density. With the exception of M1 receptor, the density of which is similar in the dorsal (motor) and ventral (limbic) striatum, other receptor subtypes were more abundant in ventral than in dorsal striatum. M1 receptor expression was unchanged between young and adult rats and decreased in senescent animals both in dorsal and ventral striatum. In dorsal striatum M2 and M5 receptor expression did not show age-related changes, whereas in ventral striatum it was slightly decreased in adult rats compared to young or senescent cohorts. M3 receptor expression did not show age-related modifications, whereas a progressive age-related decrease of M4 receptor was found, both in dorsal and ventral striatum. These data indicate a heterogeneous response to age of different muscarinic receptor subtypes. Striatal cholinergic markers are thought to correlate with cognitive impairment in aged rats. In view of this, the identification of age-related changes of striatal muscarinic receptor subtypes may contribute to develop cholinergic strategies to counter cholinergic neurotransmission changes occurring with aging.     

Influence of fasting, insulin and glucose on ghrelin in the dorsal vagal complex in rats

The dorsal vagal complex (DVC) is an important site in which ghrelin plays an orexigenic role. However, the relationship between ghrelin expression in DVC and the energy status of the organism is unclear, as well as the role of the vagus nerve in this process. In this study, ghrelin expression in DVC neurons of rats was detected, then levels of ghrelin expression were observed under the conditions of regular diet, fasting, high blood glucose, low blood glucose, and following subdiaphragmatic vagotomy and vagus nerve electrostimulation. The results showed the following: 1) there was positive staining of ghrelin neurons in DVC; 2) ghrelin protein and mRNA levels in DVC increased under fasting condition; 3) Hyperglycemia, induced by glucose production, decreased DVC ghrelin levels and levels did not increase under hypoglycemia induced by insulin injection; 4) the dorsal trunk of the subdiaphragmatic vagus transmits a stimulatory signal to increase DVC ghrelin levels, whereas the ventral trunk transmits inhibitory information; and 5) DVC ghrelin levels decreased with 20 Hz stimulation on the ventral or dorsal trunk of subdiaphragmatic vagus nerves but increased with 1 Hz stimulation on the dorsal trunk. These results indicate that endogenous ghrelin is synthesized in DVC neurons. Conditions such as fasting, hyperglycemia, and hypoglycemia result in changes in DVC ghrelin levels in which the dorsal and ventral trunks of subdiaphragmatic vagus play different modulation roles.     

Erythrocytic enzymes and antioxidant status in people with type 2 diabetes: beneficial effect of Syzygium cumini leaf extract in vitro

The aim of the present study was to investigate the effects of Syzygium cumini leaf extract (ASc), on Adenosine deaminase (ADA) and Acetylcholinesterase (AChE) activities, and also on oxidative stress parameters in erythrocytes hemolysates (RBCs) and erythrocytes membranes (ghosts) from type 2 diabetics patients (Type 2 DM) under in vitro conditions. Non protein thiol groups (NP-SH), AChE, Catalase (CAT) and Superoxide Dismutase (SOD) activities were measure in RBCs. Further, ADA activity, Thiobarbituric Acid-Reactive Substances (TBARS) levels and protein thiol groups (P-SH) were estimated in ghosts. Also, P-SH and Vitamin C (VIT C) were measure in plasma sample. The results demonstrated that ADA and AChE activities, besides TBARS levels were higher in erythrocytes of Type 2 DM, while SOD activity and NP-SH levels were decreased when compared to control group. ASc, in vitro, reduced ADA and AChE activities and some parameters of oxidative stress. Furthermore, we observed correlations between VIT C and P-SH levels, ADA activity and P-SH levels, as well as NP-SH and TBARS levels in diabetics. The results suggest that ASc in vitro is able to promote the reduction of inflammation and oxidative stress parameters, and act against biochemical changes occurring in Diabetes mellitus (DM).     

Regional and sexual differences in the size of the neuro-vascular contact surface of the rat median eminence and pituitary stalk.

The size of the neuro-vascular contact surface was estimated along the median eminence (ME) proximal pituitary stalk (PS) of adult rats using serially cut 1 micrometer thick plastic sections. It was found 26% larger in female animals. The dorsal surface of the pars tuberalis was used as reference surface, and its size was estimated in the same way. The average rate of increase of the contact surface with respect to the reference surface was 3.05 and 2.98 in females and 2.34 and 2.35 in males. The reference surface was divided into small components and also the regional distribution of the rate of increase of the contact surface was analyzed. Very folded contact surface areas were found scattered in the rostral half of the ME. Folded areas made up the ME on both sides of the midline and the dorsal and ventral surfaces of the PS, whereas relatively smooth areas are localized along the 2 margins of the ME and the 2 sides of the PS. The results were correlated with the known termination sites of dopamine and various hypothalamic hormone containing pathways.     

Histochemical studies of monoamine oxidase in experimental myocardial infarctions.

Sequential histochemical studies were conducted to determine the level of monoamine oxidase (MAO) activity in the infarcted tissue of the experimental myocardial infarction in dog. MAO activity was not found in the normal heart muscle, but the activities were present in the wall of the coronary artery histochemically. Fibroblasts and collagen fibers began to take the place of the destroyed heart muscles in the infarcted area from 10 days after the coronary occlusion in dogs, and MAO activities were noted sporadically in the fibroblasts and the interstices of the collagen fibers in the infarcted area. MAO activities increased histochemically in the fibroblasts and the fiber interstices in the infarcted area 10 days or more after the coronary occlusion. These findings suggested the presence of the active collagen metabolism outside the myocardial cells in the infarcted area in the recovery stage of the experimental myocardial infarction. It was also suggested that the interstices of the collagen fibers in the myocardial wall constituted the lymphatic ducts outside the blood vessels and that the MAO activity in serum determined by the method in which tryptamine hydrochloride was used as substrate might indicate the grade of fibrosis of the myocardial tissue in the infarcted areas.