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F Perez-Jimenez

Publications and source records attributed to F Perez-Jimenez.

5 recordsLinked to original sources
PubMed1991

Different secretory response of pancreatic isolated lobules and dissociated acini from hypothyroid rats to exogen TRH.

This paper analyses the effect of hypothyroidism on pancreatic TRH and somatostatin concentrations, as well as the action of exogen TRH on pancreatic amylase secretion from isolated lobules and dissociated acini of both healthy and hypothyroid rats. In the hypothyroid group, pancreatic TRH and somatostatin increased. In the pancreatic lobules of untreated animals, bethanechol produced stimulatory action that was inhibited by TRH. On the other hand, lobules from hypothyroid rats did not respond to bethanechol stimulation. Acini amylase secretion after bethanechol stimulation was similar in both groups, although hypothyroid animals were more sensitive to the inhibitory effect of TRH. These findings suggest the existence of a factor blocking the amylase secretion in pancreatic lobules. This agent, probably TRH, could be eliminated in the experimental model of dissociated acini.

Amylases↗
PubMed1986

Interaction of chronic alcohol administration and diet on pancreatic acinar cell metabolism in the rat.

The present study was done to determine the effect of the interaction of ethanol and an average or high-fat diet on pancreatic acinar cell function. Weight-matched groups of Sprague-Dawley rats were fed regular rat feed or average fat and high-fat liquid diets with or without 5% (w/v) concentration of ethanol for 3 months. Trypsinogen secretion was increased by the high-fat diet but not by ethanol; chymotrypsinogen secretion was decreased by the combination of ethanol and a high-fat diet, while lipase secretion was increased by a high-fat diet. Pancreatic secretory trypsin inhibitor was not significantly altered by ethanol or fat in the diet. Ethanol feeding together with a high-fat content of the diet caused complex and nonparallel changes in the secretion of the pancreatic enzymes. These data are of interest in view of the reported positive correlation between alcoholism and a high-fat content of the diet in the causation of alcoholic pancreatitis in humans.

Alcoholism↗
PubMed1986

Pancreatic acinar cell function and morphology in rats fed zinc-deficient and marginal zinc-deficient diets.

The prevalence of marginal zinc nutriture in several populations of people in this country and the lack of reports on the effect of marginal zinc nutriture in experimental animals prompted us to look at pancreatic acinar cell function and morphology in rats fed a zinc-deficient diet ad libitum: 4 and 50 ppm zinc-supplemented diets in amounts isocaloric to a zinc-deficient diet and Rodent-Blox fed ad libitum for a period of 49 +/- 1 (SEM) days. Because of a diminished rate of energy expenditure in zinc-deficient rats, animals receiving 50 ppm zinc-supplemented diets were offered less food, resulting in decreased body weight and pancreas weight, DNA, RNA, total protein, lipase, amylase, and secretion of protein. Specific changes due to zinc deficiency included (a) further decrease in body weight and (b) increase in content, specific activity, and secretion of lipase. Both the size and volume fraction of zymogen granules were reduced in zinc deficiency. The lumina of acinar and small ducts were collapsed with paucity of secretion products. Zinc deficiency may therefore lead to a defect in discharge mechanism. A further reduction in volume fraction of zymogen granules in the 4 ppm zinc-supplemented group was associated with increased secretion of serine proteases (trypsinogen and chymotrypsinogen), which constitute approximately 46% of total secretory protein in the pancreas under normal dietary conditions. This indicated an accelerated discharge due to an unknown mechanism. Changes in the secretion of digestive enzymes in the present study simulated ethanol-induced secretory alterations that were previously observed. Because abnormal zinc nutriture and chronic alcoholism are commonly associated, it is speculated that zinc deficiency may play a role in the ethanol-induced secretory alterations.

Amylases↗
PubMed1986

Interaction between marginal zinc deficiency and chronic alcoholism: pancreatic structure and function in rats in vitro.

The present study was done to determine interaction of ethanol and marginal zinc nutriture on morphology and function of rat pancreas. Sprague-Dawley rats were maintained on Wayne Rodent-Blox ad libitum; marginal zinc-deficient diet plus ethanol ad libitum and pair fed with animals fed marginal zinc-deficient liquid diet and zinc-supplemented liquid diet with ethanol for 33 (+/- 1 SEM) days. Body, pancreas, liver, heart, and kidney weights were determined, and studies of pancreatic DNA, RNA, total proteins and newly labeled proteins, amylase, lipase, trypsinogen, and chymotrypsinogen were done on pancreatic lobules in vitro. Ethanol feeding independent of the zinc content of the diet caused a decrease in zinc content of the liver, body weight, liver and pancreas weight, pancreatic DNA, total protein, and amylase concentration and an increase in lipase and trypsinogen concentrations and in secretion of amylase and lipase. Interaction of the marginal zinc diet and ethanol feeding resulted in a decreased synthesis of RNA and secretion of newly synthesized protein and an increase in secretion of serine proteases. Morphological studies revealed a reduction in the number of zymogen granules in animals fed low levels of zinc, also with an accumulation of lipid droplets when the diet contained ethanol. These studies confirmed our previous observations of specific injury to the pancreas due to marginal zinc nutriture or to ethanol, independent of each other. Marginal zinc nutriture in concert with ethanol resulted in impaired RNA synthesis and secretion of nascent proteins and increased secretion of serine proteases. These data indicate that altered zinc metabolism induced by ethanol per se may contribute to ethanol-induced disturbance of pancreatic function.

Alcoholism↗