Ultrasonic duplex system to facilitate assessment of portal blood flow velocity

The usefulness of an ultrasonic duplex system to assess portal blood flow was investigated. In a model involving a steady flow through a vinyl tube in agar, there was a significant linear correlation between the maximum blood flow velocity measured by this system (V-max) and the mean blood flow velocity calculated from the actually measured blood flow volume (V-mean), that is, V-mean = 0.53 X V-max was obtained (r = 0.994; n = 47). This equation was used to calculate the mean portal blood flow velocity by this system (V-dopp) in 10 patients with liver disease, and the findings were compared with data simultaneously obtained by cineangiographic mapping of Lipiodol droplets released into the portal vein through a catheter placed in situ at the time of surgery (V-cine). A linear correlation between V-dopp and V-cine was statistically significant (r = 0.970; n = 13), and the regression line was V-cine = 1.29 X V-dopp -2.11. The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.     

Sympathoadrenal excitation and inhibition by lower brainstem stimulation in cats

Effects of stimulation of brainstem sites on hemodynamics and plasma catecholamine levels were assessed in cats under chloralose-urethane anesthesia. Pressor areas of the dorsal medulla (DM) and ventrolateral medulla (VLM) and the depressor area of the paramedian reticular nucleus (PRN) were stimulated electrically using a monopolar electrode, or chemically using sodium glutamate microinjection. Plasma levels of norepinephrine (NE) and epinephrine (EPI) were measured in caval blood above the adrenal veins. Electrical stimulation of the DM and VLM produced increases in blood pressure and in plasma NE and EPI levels that were enhanced after acute vagotomies. The NE and EPI responses were attenuated after acute, bilateral adrenalectomies, confirming augmented adrenomedullary secretion, whereas the pressor responses were intact. Injection of sodium glutamate into the same pressor regions of the DM or VLM also produced pressor responses and elevated plasma catecholamine levels, indicating that the responses resulted from activation of neuronal perikarya. Stimulation of the PRN attenuated pressor and catecholamine responses during stimulation of the DM and VLM. The results indicate that pressor responses during stimulation of the DM and VLM are due at least partly to activation of perikarya in these regions, are associated with but not dependent on adrenomedullary activation, and are enhanced after vagotomy; and that neurons of the PRN exert inhibitory modulation of the pressor and adrenomedullary responses during stimulation of VLM and DM.     

Behavioral pharmacological action of Ca-4-(3,5-dihydroxy-3-methylpenthylamido) butyrate (mevalonic GABA, MV-GABA)

The behavioral pharmacological effects of Ca-4-(3,5-dihydroxy-3-methylpenthylamido) butyrate (mevalonic-GABA, MV-GABA), a new GABA derivative were studied in comparison with those of Ca-hopantenate (HOPA) in mice. MV-GABA had no effect on the general behavior and electric shock-induced fighting behavior. The dosage of MV-GABA which caused locomotor hypoactivity produced an impairment of the rotarod performance. MV-GABA inhibited the hyperactivity induced by a dopamine (DA) agonist (methamphetamine) and acetylcholine (ACh) antagonists (scopolamine and atropine) at a dose which did not affect locomotor activity in normal mice. MV-GABA prolonged the pentobarbital-Na-induced sleeping time, and it prolonged the latencies until convulsion and death after administration of strychnine. MV-GABA and HOPA antagonized the electroconvulsive shock-induced amnesia in the passive avoidance response of mice. These results suggest that MV-GABA has effects on the central nervous systems, in particular, ACh and DA neural systems. The actions of MV-GABA were qualitatively similar to those of HOPA except for the effect on the DA neural system.     

Effect of testosterone and anabolic steroids on the size of sebaceous glands in power athletes

The effect of testosterone and anabolic steroids on the size of sebaceous glands was studied by means of interactive morphometry in skin biopsies of power athletes. The subjects used self-administered high doses of testosterone and anabolic steroids during a 4-week strength training period. After 4 weeks' use of hormones, the area of sectioned sebaceous glands enlarged significantly by a factor of 89.2% (p less than 0.005). The number of cells in the so-called differentiating cell pool (DCP) and in the undifferentiated cell pool (UCP) also increased significantly (p less than 0.025, p less than 0.05, respectively). The size of the area occupied by UCP cells increased significantly (p less than 0.05). The study suggests that high doses of testosterone and anabolic steroids lead to an enlargement of sebaceous glands in male power athletes.