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Biomedical subjects

T J Ihrig

Publications and source records attributed to T J Ihrig.

14 recordsLinked to original sources

Effect of alcohol on the plasma cAMP response to glucagon.

Prior studies indicated that acute ethanol feeding induced a decrease in adrenergic sensitivity as measured by the plasma cAMP response to isoproterenol. In this report we show that two hours after acute ethanol ingestion the plasma cyclic AMP levels were increased 8.5 fold 6 minutes after glucagon injection. Saline controls showed a 35 fold increase in plasma cAMP levels after glucagon injection. It is suggested that the decreased response caused by ethanol may be due to a decrease in the sensitivity of glucagon receptors.

Animals↗

Reduced adrenergic sensitivity in vivo in acute ethanol-fed rats.

Prior studies indicate ethanol feeding induces adrenergic subsensitivity in vitro, as measured by cyclic adenosine monophosphate (cAMP) response of tissues to norepinephrine (NE). In this report we show acute ethanol feeding induces a depressed level of adrenergic sensitivity in vivo, as measured by plasma cAMP response to isoproterenol. Two hours after intragastric feeding of ethanol (6 gm/kg) to rats, there was a decrease in plasma cAMP response to intravenous isoproterenol, compared to dextrose controls. This decrease was the same in animals with blood ethanol levels averaging 68 mg/dl or 193 mg/dl. This data is consistent with the hypothesis that ethanol induces adrenergic subsensitivity.

Alcoholic Intoxication↗

Cholesterol ester hydrolysis by homogenates of whole testis, seminiferous tubules and interstitial cells of mature rats.

The characteristics and localization of a cholesterol ester hydrolase enzyme in homogenates of whole testis and in isolated seminiferous tubules and interstitial cells of mature rats have been investigated. Hydrolysis of cholesteryl [1(-14)C]oleate occurred at an optimum pH of 7.0, was linearly related to time up to 5--6 h of incubation and increased linearly up to 0.25 mg protein/incubation. Hydrolytic activity was inhibited by increasing the incubation temperature from 29 to 41 degrees C and by sonication. Cholesterol ester hydrolase activity/mg protein was three times greater in homogenates of seminiferous tubules than in interstitial cells. Cholesterol ester hydrolase may function to provide precursors for use in seminiferous tubular steroid hormone biosynthesis or germ cell maturation.

Animals↗

Concentrations of free and esterified cholesterol in the testes of maturing rabbits.

Levels of cholesterol and cholesterol esters were established in the testes of maturing New Zealand white rabbits. Free cholesterol levels remained relatively constant throughout pre- and post-pubertal development. The total cholesterol, cholesterol esters and percentage esterified cholesterol values were highest during the prepubertal period and decreased steadily thereafter, reaching their lowest after 90 days of age. Correlations of these findings with hormonal and morphological changes during testicular development are discussed.

Age Factors↗

Morphologic study of intermediate filaments in rat hepatocytes.

Rat liver perfused with 0.5% Triton X-100 for 15 to 90 min followed by 1% sodium dodecyl sulfate for 30 min were studied by electron microscopy and polyacrylamide gel electrophoresis. After 15 min of perfusion, a rich network of intermediate filaments and microtubules was visualized in the cytoplasm of hepatocytes. Using stereopairs, branching was visualized. Connections of filaments were noted with nuclei, centrioles, microtubules, vesicles, and rough endoplasmic reticulum. The existence of connections supported the concept that intermediate filaments may function to integrate mechanically the cytoplasmic space as postulated by Lazarides.

Animals↗

Effect of ethanol and chlorpromazine on transhepatic transport and biliary secretion of horseradish peroxidase.

In order to demonstrate the effect to the acute administration of ethanol and chlorpromazine (CPZ) on bile flow and transhepatic transport of horseradish peroxidase (HRP) into bile, male rats were administered either 5 gm per kg ethanol intragastrically (E-rats) or 3 mg per kg CPZ intraperitoneally (CPZ rats). Control rats (C-rats) received saline. Two hours after ethanol feeding or 90 min after CPZ injection HRP was injected into the portal vein, and bile samples were collected at 10-min intervals for 2 hr. Tissue samples were removed at 1, 10, 60, and 120 min to study HRP transport using electron microscopic cytochemical localization. Bile flow was reduced (p less than 0.001) both in E- and CPZ-rats compared to C-rats. In E-rats HRP secretion was significantly decreased at 30 and 40 min post-HRP injection (p less than 0.05) and the peak rate of HRP secretion was delayed by 10 min compared to C-rats. Uptake and transhepatic transport of HRP were similar to controls. These results suggest that bile secretion and flow were impaired by ethanol. CPZ inhibited secretion of HRP significantly (p less than 0.001) during the first hr after HRP injection and by 25% after 2 hr. In CPZ rats studied cytochemically HRP reaction product decreased in the cytoplasm of hepatocytes 10 min after HRP injection (p less than 0.01). These findings suggest that acute CPZ administration caused an inhibition of the uptake of HRP as well as secretion and bile flow.

Animals↗