Fujio Yamagishi

Acute effects of the calcium antagonist, nifedipine, on blood pressure, pulse rate, and the renin-angiotensin-aldosterone system in patients with essential hypertension

Ten milligrams nifedipine was administered orally to young and old persons with or without hypertension, and the acute effects of nifedipine on the renin-angiotensin-aldosterone system were studied one half to 3 hours later. Nifedipine reduced blood pressure and increased pulse rate in young and old persons with or without hypertension. Simultaneously, nifedipine produced a significant increase of plasma renin activity in young persons with or without hypertension but failed to do so in old persons with or without hypertension. As a result, angiotensin I and II increased significantly in young persons but not in old persons. Hydralazine elevated aldosterone concentration by stimulating the renin-angiotensin system but nifedipine failed to do so despite its effect on the renin-angiotensin system in young individuals. Since calcium is required to secrete aldosterone, it is suggested that nifedipine blocked aldosterone secretion by the agents calcium antagonizing action.

Effects of substance P on pancreatic exocrine secretion stimulated by secretin, dopamine and cholecystokinin in dogs

1. The effect of substance P (SP) on pancreatic exocrine responses to exogenous cholecystokinin, secretin, and dopamine, were studied in the isolated and blood‐perfused pancreas of dogs.

Effects of three purine-related compounds on pancreatic exocrine secretion in the dog

1. The effects of adenosine, adenosine 5′‐triphosphate (ATP) and inosine on pancreatic exocrine secretion were investigated in the vascularly isolated and self‐hacmoperfused dog pancreas. Drugs were injected close‐arterially (i.a.) in a single bolus.

Effects of nitroprusside on pancreatic exocrine secretion and cyclic nucleotide concentration in the dog pancreas

The effects of intravenous injection of nitroprusside on pancreatic exocrine secretion and on pancreatic cyclic AMP and cyclic GMP concentrations of mongrel dogs were investigated. Nitroprusside (10-100 micrograms/kg) increased the exocrine secretion together with the increase in cyclic GMP concentration dose dependently but did not affect the cyclic AMP concentration. These results suggest that nitroprusside causes exocrine secretion from the dog pancreas mediated through an increase of intracellular cyclic GMP concentration.

EFFECTS OF A SYNTHESIZED PHOSPHODIESTERASE INHIBITOR, ZSY‐27, ON PANCREATIC EXOCRINE SECRETION OF THE DOG

1. The effects of a synthesized phosphodiesterase inhibitor, ZSY‐27, on the secretion of pancreatic juice were investigated in dog isolated and blood‐perfused pancreas, and compared with those of secretin and dopamine.

Metoclopramide enhances bethanechol-induced pancreatic exocrine secretion of the dog.

1. The effects of metoclopramide on pancreatic exocrine secretion were investigated in the pentobarbitone‐anaesthetized dog. All drugs were injected into the femoral vein.

EFFECT OF SECRETAGOCUES ON PANCREATIC EXOCRINE SECRETION IN THE MONKEY AND THE DOG

1. The effects of secretin, cholecystokinin, dopamine, histamine and acetylcholine on the secretion of pancreatic juice were investigated in the monkey and the dog.