Effects of somatotropin in rats acutely exposed to adverse environments

1961 ◽  
Vol 16 (1) ◽  
pp. 123-126 ◽  
Author(s):  
Henry B. Hale ◽  
Roy B. Mefferd

Metabolic effects of acute (24-hr.) exposure to low barometric pressure (380 mm Hg), heat (35°C), or cold (2°C) were determined in fasting rats which had received subcutaneous injections of somatotropin (0.5 mg/100 gm b.wt.) 24 hours before and immediately before exposure. Comparison was made with rats exposed to the same conditions without pretreatment with somatotropin and with controls held under neutral conditions of temperature and pressure (24°C, 750 mm Hg). Somatotropin modified environmentally induced changes in 24-hour urinary excretion of urea, uric acid and phosphate and the urinary Na/K, Ca/P and uric acid/creatinine ratios. Suggestive evidence was thus obtained to support the hypothesis that somatotropin contributes to homeostasis. Submitted on October 26, 1959

1958 ◽  
Vol 195 (3) ◽  
pp. 735-738 ◽  
Author(s):  
Roy B. Mefferd ◽  
Henry B. Hale

The metabolic responses of rats acclimated to different temperatures (3°, 24° and 35°C) were compared during a 24-hour fasting exposure to low barometric pressure (380 mm Hg). Determinations included fasting weight loss, water intake, urine volume and urinary excretion of Na, K, Mg, Ca, PO4, urea, uric acid, creatinine, creatine, taurine, ß-alanine, glycine, α-alanine, valine + methionine, serine, threonine, tyrosine, glutamic acid, aspartic acid, lysine, arginine and histidine. Since the altitude tests were made at a neutral temperature (25°C) the altitude responses, per se, were determined by comparing the ground and altitude responses of each acclimated group at neutral temperatures. These comparisons revealed that the acclimated state of the rats exercised a strong influence on the altitude response for most of the variables. There were significant intergroup differences in this response for all variables except phosphate, urea, taurine, valine + methionine, serine, histidine and the Mg/Ca ratio.


1961 ◽  
Vol 16 (2) ◽  
pp. 243-246 ◽  
Author(s):  
Henry B. Hale ◽  
Roy B. Mefferd

Effects of somatotropin (STH, growth hormone) in low dosage on metabolic functions were determined in adult male rats acclimated to hot, neutral or cold environments or to low barometric pressure. Urinary determinations (24-hour, fasting) provided the means for evaluating nitrogen and mineral metabolism. The interplay between STH and environmental factors thus received some clarification. STH had certain effects in normal rats which were clearly heat- or altitude-mimetic. In combination, STH and heat had synergistic effects on urea, phosphate and the calcium/phosphorus ratio; and STH and altitude acted synergistically on phosphate and the sodium/potassium and calcium/phosphorus ratios. STH and cold had antagonistic effects on urea, uric acid and the uric acid/creatinine ratio, but synergism was evident in the sodium/potassium ratio. The effects of STH during the initial stage of recovery from heat, altitude or cold were also studied. While some of the recovery reactions were augmented by STH, others were blocked or at least diminished, and there were instances where STH had normalizing effects. Submitted on October 6, 1960


1958 ◽  
Vol 194 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Henry B. Hale ◽  
Roy B. Mefferd

Metabolic effects of chronic exposure to combinations of adverse environmental influences were studied in rats. During exposures lasting 12 weeks, rats were subjected to the barometric pressure equivalent to 18,000 feet altitude at temperatures ranging from 5° to 34°C. Controls at the various temperatures were held at ground level (700 ft. above sea level). Biweekly observations showed that metabolic functions (water, electrolyte and nitrogen) were influenced primarily by the thermal factors, but altitude effects could also be distinguished. Observations are reported for survival, body weight change, water and food intake, urine volume and the urinary excretion of Na, K, PO4, Mg, Ca, urea, uric acid, creatinine, taurine and 10 amino acids.


1999 ◽  
Vol 68 (2) ◽  
pp. 175-180 ◽  
Author(s):  
Melissa L. Davis-Whitenack ◽  
Bernice Adeleye ◽  
Barbara J. Stoecker

1984 ◽  
Vol 247 (4) ◽  
pp. E505-E512 ◽  
Author(s):  
C. B. Niewoehner ◽  
D. P. Gilboe ◽  
G. A. Nuttall ◽  
F. Q. Nuttall

Twenty-four-hour-fasted rats were given fructose (4 g/kg) by gavage. Fructose absorption and the portal vein, aorta, and hepatic vein plasma fructose, glucose, lactate, and insulin concentrations as well as liver fructose and fructose 1-P, glucose, glucose 6-P, UDPglucose, lactate, pyruvate, ATP, ADP, AMP, inorganic phosphate (Pi), cAMP, and Mg2+, and glycogen synthase I and phosphorylase alpha were measured at 10, 20, 30, 40, 60 and 120 min after gavage. Liver and muscle glycogen and serum uric acid and triglycerides also were measured. Fifty-nine percent of the fructose was absorbed in 2 h. There were modest increases in plasma and hepatic fructose, glucose, and lactate and in plasma insulin. Concentrations in the portal vein, aorta, and hepatic vein plasma indicate rapid removal of fructose and lactate by the liver and a modest increase in production of glucose. The source of the increase in plasma lactate is uncertain. Hepatic glucose 6-P increased twofold; UDPglucose rose transiently and then decreased below the control level. Fructose 1-P increased linearly to a concentration of 3.3 mumol/g wet wt by 120 min. There was no change in ATP, ADP, AMP, cAMP, Pi, or Mg2+. Serum triglycerides and uric acid were unchanged. Glycogen synthase was activated by 20 min without a change in phosphorylase alpha. This occurred with a fructose dose that did not significantly increase either the liver glucose or fructose concentrations. Liver glycogen increased linearly after 20 min, and glycogen storage was equal in liver (38.4%) and muscle (36.5%).(ABSTRACT TRUNCATED AT 250 WORDS)


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Valter Tadeu Boldarine ◽  
Ellen Joyce ◽  
Amanda Paula Pedroso ◽  
Mônica Marques Telles ◽  
Lila Missae Oyama ◽  
...  

AbstractMenopause may be accompanied by abdominal obesity and inflammation, conditions accentuated by high-fat intake, especially of saturated fat (SFA)-rich diets. We investigated the consequences of high-SFA intake on the fatty acid (FA) profile of monoglycerides, diglycerides and cholesteryl esters from retroperitoneal white adipose tissue (RET) of rats with ovariectomy-induced menopause, and the effect of oestradiol replacement. Wistar rats were either ovariectomized (Ovx) or sham operated (Sham) and fed either standard chow (C) or lard-enriched diet (L) for 12 weeks. Half of the Ovx rats received 17β-oestradiol replacement (Ovx + E2). Body weight and food intake were measured weekly. RET neutral lipids were chromatographically separated and FAs analysed by gas chromatography. Ovariectomy alone increased body weight, feed efficiency, RET mass, leptin and insulin levels, leptin/adiponectin ratio, HOMA-IR and HOMA-β indexes. OvxC + E2 showed attenuation in nearly all blood markers. HOMA-β index was restored in OvxL + E2. OvxC showed significantly disturbed SFA and polyunsaturated FA (PUFA) profile in RET cholesteryl esters (CE). OvxC also showed increased monounsaturated FA (MUFA) in the monoglyceride diglyceride (Mono–Di) fraction. Similar changes were not observed in OvxL, although increased SFA and decreased PUFA was observed in Mono–Di. Overall, HRT was only partially able to revert changes induced by ovariectomy. There appears to be increased mobilization of essential FA in Ovx via CE, which is a dynamic lipid species. The same results were not found in Mono–Di, which are more inert. HRT may be helpful to preserve FA profile in visceral fat, but possibly not wholly sufficient in reverting the metabolic effects induced by menopause.


1995 ◽  
Vol 268 (1) ◽  
pp. E1-E5 ◽  
Author(s):  
A. Quinones Galvan ◽  
A. Natali ◽  
S. Baldi ◽  
S. Frascerra ◽  
G. Sanna ◽  
...  

Although hyperuricemia is a frequent finding in insulin-resistant states, insulin's effect on renal uric acid (UA) handling is not known. In 20 healthy volunteers, diastolic blood pressure, body weight, and fasting plasma insulin were positively (and age was negatively) related to fasting plasma UA concentrations, together accounting for 53% of their variability. During an insulin clamp, urine flow was lower than during fasting conditions (1.01 +/- 0.12 vs. 1.56 +/- 0.32 ml/min, P = 0.04), whereas creatinine clearance was unchanged (129 +/- 7 and 131 +/- 9 ml/min, P = not significant). Hyperinsulinemia did not alter serum UA concentrations (303 +/- 13 vs. 304 +/- 12 microM) but caused a significant decrease in urinary UA excretion [whether expressed as absolute excretion rate (1.66 +/- 0.21 vs. 2.12 +/- 0.23 mumol/min, P = 0.03), clearance rate (5.6 +/- 0.8 vs. 7.3 +/- 0.8 ml/min, P = 0.03), or fractional excretion (4.48 +/- 0.80 ml/min vs. 6.06 +/- 0.64%, P < 0.03)]. Hyperinsulinemia was also associated with a 30% (P < 0.001) fall in urine Na excretion. Fractional UA excretion was related to Na fractional excretion under basal conditions (r = 0.59, P < 0.01) and during the insulin period (r = 0.53, P < 0.02). Furthermore, the insulin-induced changes in fractional UA and Na excretion correlated with one another (r = 0.66, P < 0.001). Physiological hyperinsulinemia acutely reduces urinary UA and Na excretion in a coupled fashion.


1975 ◽  
Vol 23 (10) ◽  
pp. 707-721 ◽  
Author(s):  
W Straus

The reabsorption of horseradish peroxidase (HRP) by the proximal tubule cells of rat kidneys was investigated by measuring the concentration of HRP in total particulate fractions of the cortex 1/4 and 1 hr after intravenous injection, and by correlated cytochemical observations. When compared to the corresponding values of the control animals, the concentration of HRP 1 hr after injection was decreased approximately 10-fold in the renal cortex of rats which had received an intravenous injection of hypertonic saline or two subcutaneous injections of mannitol. The plasma clearance and the urinary excretion of HRP were not altered significantly after injection of hypertonic saline, but the plasma clearance was decreased and the urinary excretion increased after injection of mannitol. When the dose of injected HRP was varied, the reabsorption of HRP by the renal cortex was proportional to the dose in the experimental and the control animals. Cytochemical staining for peroxidase activity also showed that the phagosomes and phagolysosomes of the proximal tubule cells contained much less peroxidase in the experimental rats than in the control rats. After injection of mannitol, large vacuoles appeared in the proximal tubule cells. The vacuoles often contained peroxidase-positive granules (phagosomes) which varied in diameter from the limit of microscopic visibility up to several microns. Most of the vacuoles did not react for acid phosphatase activity, but lysosomes were often aggregated around the vacuoles and seemed to release acid phosphatase into the cytoplasm. Certain analogies between the reabsorption of protein and that of water by the proximal tubule cells are discussed.


2019 ◽  
Author(s):  
Vanessa Teckentrup ◽  
Sandra Neubert ◽  
João C. P. Santiago ◽  
Manfred Hallschmid ◽  
Martin Walter ◽  
...  

AbstractMetabolic feedback between the gut and the brain relayed via the vagus nerve contributes to energy homeostasis. We investigated in healthy adults whether non-invasive stimulation of vagal afferents impacts energy homeostasis via efferent effects on metabolism or digestion. In a randomized crossover design, we applied transcutaneous auricular vagus nerve stimulation (taVNS) while recording efferent metabolic effects using simultaneous electrogastrography (EGG) and indirect calorimetry. We found that taVNS reduced gastric myoelectric frequency (p =.008), but did not alter resting energy expenditure. We conclude that stimulating vagal afferents induces gastric slowing via vagal efferents without acutely affecting net energy expenditure at rest. Collectively, this highlights the potential of taVNS to modulate digestion by activating the dorsal vagal complex. Thus, taVNS-induced changes in gastric frequency are an important peripheral marker of brain stimulation effects.


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