Age-related changes in gene expression patterns of matrix metalloproteinases and their collagenous substrates in mandibular condylar cartilage in rats

Matrix metalloproteinases (MMPs) have been implicated in physiological cartilage matrix remodelling as well as in pathological and invasive extracellular matrix remodelling of tissue. Age-related changes in the gene expression patterns of MMPs in mandibular condylar cartilages (MCCs) were analysed. We examined the gene expression patterns of Mmp-8 and -13 and their substrates, Col1a1, Col2a1 and Col10a1, in MCC of growing and ageing rats. Temporomandibular joints of male Wistar rats aged 4, 8, 16 and 32 weeks were subjected to in situ hybridization analysis. Histologically, MMCs showed characteristics of growth plate cartilage at ages 4 and 8 weeks, and more closely resembled articular cartilage thereafter. Mmp-8 was expressed in the cells in all cartilaginous cell layers at ages 4 and 8 weeks, and then was localized only in the mature cells at ages 16 and 32 weeks. Whereas Mmp-13 expression was limited to the lowermost hypertrophic chondrocytes in the growth stage, mature chondrocytes instead of hypertrophic chondrocytes expressed Mmp-13 in adult non-hypertrophic MCC. Because Mmp-8 and -13 expression overlapped with Col2a1 and Col10a1, chondrocytes could play a pivotal role in degradation as well as production of the cartilaginous matrix in MCC.     

Prevention of hypertensive crisis with ATP during anesthesia for pheochromcytoma

In the anesthetic management of five patients undergoing excision of pheochromocytoma, adenosine triphosphate (ATP) was used for the purpose of regulating systemic arterial pressure during the period of tumor manipulation. ATP was administered at doses of 0.05–0.4mg/kg/min. Systemic arterial pressure showed a significant decrease from 162 ± 17/103 ± 11mmHg before manipulation to 136 ± 21/81 ± 10mmHg during the manipulation period. The plasma catecholamine levels showed significant increases in this period. Immediately after excision, the systemic arterial pressure was maintained at normal levels (118 ± 13/75 ± 16mmHg) by fluid replacement and discontinuation of ATP administration, subsequently becoming 129 ± 19/79 ± 16mmHg. The heart rate was very stable and tachycardia did not ocurr during the manipulation period. Only one arrhythmic episode ocurred in one patient. The systemic vascular resistance index was significantly lower during the manipulation period than before it. It was therefore considered that ATP was useful as an agent for controlling arterial pressue during the anesthesia for pheochromocytoma.(Murata K, Sodeyama O, Ikeda K et al.: Prevention of hypertensive crisis with ATP during anesthesia for pheochromocytoma. J Anesth 1: 162–167, 1987)     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: FUNCTIONS OF ANGIOTENSIN PEPTIDES IN THE ROSTRAL VENTROLATERAL MEDULLA

• 1 It was first shown several years ago that the rostral part of the ventrolateral medulla (VLM) contains a high density of receptor binding sites for angiotensin II (AngII). In the present paper we briefly review recent studies aimed at determining the actions of both exogenous and endogenous angiotensin peptides in the rostral VLM, as well as their specific sites of action.
• 2 The results of these studies have shown that angiotensin peptides can excite pressor and sympathoexcitatory neurons in the rostral VLM, but do not appear to affect non-cardiovascular neurons in this region.
• 3 It is known that pressor neurons in the rostral VLM include both catecholamine and non-catecholamine neurons. There is evidence that, at least in conscious rabbits, both of these types of neurons are activated by AngII. The specific endogenous angiotensin peptide or peptides that affect pressor neurons in the rostral VLM have not yet been definitively identified.
• 4 It is also possible that different angiotensin peptides may have different effects on pressor neurons in the rostral VLM, mediated by different receptors. Further studies will be needed to define these different functions as well as the specific receptors and cellular mechanisms that subserve them.

     

Purification and Partial Characterization of an Indomethacin Hydrolyzing Enzyme from Pig Liver

Purpose. Indomethacin is well known to be metabolized via O-demethylation and N-deacylation. In this paper we found an enzyme involved in the hydrolysis of amide-linkage of indomethacin and partially characterized it as well as its substrate specificity. Methods. An indomethacin hydrolyzing enzyme was purified to homogeneity from pig liver microsomes using columns of Q-Sepharose, Red-Sepharose and Blue-Sepharose. The enzyme activity was assayed by measuring of -chlorobenzoic acid liberated from indomethacin by HPLC. Results. The purified enzyme effectively hydrolyzed the amide linkage in indomethacin but not those in -naphthylacetate and -nitrophenylacetate, which are typical substrates for carboxylesterase. The subunit molecular mass of the enzyme was 65 kDa according SDS-polyacrylamide gel electrophoresis. The Michaelis constant (Km) and maximum velocity (Vmax) values for indomethacin were 67.8 µM and 9.02 nmol/min/mg protein, respectively. The amino acid sequence analysis of the enzyme after cyanogen bromide cleavage showed high homology with a mouse carboxylesterase isozyme designated as ES-male. The activity of indomethacin hydrolysis was relatively high in the pig, rabbit and human liver homogenate, but not in those from rat and mouse. On the other hand, purified human liver carboxylesterases pl 5.3 and 4.5, and pig liver carboxylesterases have no catalytic activity for indomethacin. Conclusions. These results indicate that the hydrolysis of amide-linkage of indomethacin in humans would be associated with an enzyme similar to the indomethacin hydrolyzing enzyme from pig liver microsomes described here.     

Argyrophilic nucleolar organizer regions of breast tumors: Assessment of aspirated cytological materials

To investigate the correlation between argyrophilic nucleolar organizer regions (Ag-NORs)and the malignant potential of breast tumors, we analyzed Ag-NORs of cytological specimens obtained from 190 patients with various types of breast disease by preoperative aspiration biopsy. The average number of Ag-NORs per nucleus was defined as the Ag-NOR score. The Ag-NOR score was 5.7 +/- 1.7 in the group of women with breast carcinoma (n =70), 2.6= 0.4 in the group with fibroadenoma (n= 54) and 2.9= 0.6 in the group with mastopathy (n= 66). The level was significantly higher in breast carcinoma than in each benign disease(P < 0.001 in both cases). The score was 6.5 +/- 2.3 in the group with four or more metastatic lymph nodes (n = 21), 5.2+/- 1.2 in the group with one to three metastatic lymph node (n= 10) and 5.1+/- 1.1 in that with no metastatic lymph node (n = 39);the score was significantly (P < 0.05) higher in the groups with four or more metastatic lymph modes than in the other groups, respectively. Thus, a correlaton was observed between the Ag-NOR score and lymph node status. These data suggest that a higher Ag-NOR score reflects high-grade malignancy.     

Oxygen uptake and carbon dioxide elimination during epinephrine-induced arrhythmias in humans

Key words  cardiac arrhythmias - oxygen uptake - carbon dioxide elimination     

Comparative cardiovascular effects of SNP,ATP and phentolamine during norepinephrine-induced hypertension in dogs

There has been no study comparing the advantage and disadvantage of various antihypertensive agents during surgery for pheochromocytomas because the study is difficult in clinical setting. In the present experiments using dogs, after increasing the arterial blood pressure with norepinephrine, we decreased it to the baseline with sodium nitroprusside (SNP), adenosine triphosphate (ATP), or phentolamine (PE) and compared the hemodynamic changes. A hyperdynamic state was found with ATP and with PE, but not with SNP. The norepinephrine-induced pulmonary hypertension could be successfully treated with SNP, but not with ATP or PE. The reason for these differences are thought to be the different vasodilative properties on peripheral arteries and veins. We conclude that agents that dilates the arteries and veins should be used to regulate the arterial pressure during surgical removal of a pheochromocytoma.(Murata K, Takahashi H, Ikeda K: Comparative cardiovascular effects of SNP, ATP and phentolamine during norepinephrine-induced hypertension in dogs. J Anesth 5: 396–403, 1991)     

抗体夹心酶联免疫吸附法测定重组E.coli L-门冬酰胺酶研究

用重组E.coliL-门冬酰胺酶免疫家兔，DEAE-纤维素柱层析纯化IgG，采用二步戊二醛交联法将辣根过氧化物酶标记抗体，建立抗体夹心酶联免疫吸附法，测定大鼠血浆中重组E.coliL-门冬酰胺酶浓度。本测定方法的线性范围为1～64U/L，灵敏度为0.4U/L。建立的抗体夹心酶联免疫吸附法测定大鼠血浆中重组E.coliL-门冬酰胺酶具有良好的精密度、回收率、灵敏度和特异性。