Effects of hypophysectomy and corticosterone acetate treatment on hepatic lipid composition in the chick (Gallus domesticus) embryo

Lipid is transferred from yolk to liver and to other tissues at an accelerated rate after 16 days of incubation in the intact chicken embryo. Hypophysectomy (partial decapitation) at 36 hr of incubation reduced liver lipid content on Days 16 and 18. The greatest losses on Day 18 were among cholesterol esters but decreased unesterified cholesterol and phospholipid were also observed. Treatment of hypophysectomized embryos with corticosterone acetate (300 [mu]g per day on Days 13, 14, 15) partially restored total hepatic lipid content to control values on Day 16, with an even greater effect on 18 days of incubation. Most of the increase in lipid occurred in the triglyceride fraction. Liver cholesterol content also increased in response to hormone but neither cholesterol esters nor phospholipids were elevated by corticosterone acetate. Hypophysectomy interferes with the absorption of lipids from yolk and with fat deposition in embryonic liver. However, treatment of hypophysectomized embryos with corticosterone acetate did not correct the major defects in hepatic lipid content. Therefore, fat metabolism and transport of yolk lipids to the embryo during the last week of incubation does not depend exclusively on adrenal glucocorticoids.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24445/1/0000719.pd

Ontogeny of endocrine control of osmoregulation in chick embryo : I. Role of pituitary gland in distribution of water and ions among embryonic and extraembryonic compartments

Distribution of water and of Na+ and Cl- ions in blood and in allantoic, amniotic, and yolk sac fluids were observed during ontogeny of the chick embryo. A possible osmoregulatory role for pituitary hormones was inferred from differences in ionic concentrations and volumes of these compartments in partially decapitated (hypophysectomized) embryos and in intact and windowed-control embryos observed on Day 16.5 of incubation (20-21 days to hatching). Na+-K+-ATPase activity was also measured in both mesonephric and metanephric kidneys in control and in hypophysectomized and pituitary transplanted embryos. Some osmoregulatory defects in hypophysectomized embryos were reversed by transplantation of anterior and posterior lobes of the pituitary for 1 week beginning on Day 9 of incubation. Allantoic fluid volume was reduced and Na+ and Cl- concentrations were elevated in this compartment in hypophysectomized embryos. Pituitary transplantation restored both measurements to control values. Amniotic fluid volume was not significantly changed by hypophysectomy when compared with windowed controls. Amniotic Cl- concentration was also insensitive to hypophysectomy. Pituitary transplantation lowered amniotic fluid volume slightly, but elevated its Cl- concentration significantly. Hypophysectomy reduced the percentage water content in yolk sac and significantly increased hydration of the embryo. Pituitary transplantation partially restored fractional water content of yolk to control levels and reversed body hydration. Hypophysectomy and transplantation had no significant effects on serum Na+ concentrations in the 16.5-day-old embryo. Activities of renal Na+-K+-ATPase were not significantly changed in mesonephros or metanephros by hypophysectomy or transplantation of one pituitary gland. Hormones of the pituitary gland appear to be required for normal distribution of water and ions in the chick embryo at 16.5 days of incubation. Possible target organs include both embryonic kidneys, but activities of renal Na+-K+-ATPase seem to be independent of pituitary hormones. Certain corrective actions obtained in response to metabolic hormones (thyroxine and corticosterone) suggest that some osmoregulatory defects observed in hypophysectomized embryos could result from impaired metabolism and a reduced rate of maturation rather than from the absence of specific osmoregulatory hormones of the pituitary gland.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23815/1/0000054.pd

Ontogeny of endocrine control of osmoregulation in chick embryo : II. Actions of prolactin, arginine vasopressin, and aldosterone

Actions of ovine prolactin (oPRL), arginine vasopressin (AVP), and aldosterone on volume of allantoic fluid and its Cl- concentration and on renal Na+-K+-ATPase activities in mesonephros and metanephros were examined at various times during ontogeny of the chick embryo. Ovine PRL decreased allantoic fluid volume and lowered Cl- concentration in this compartment when injected for various periods prior to 14 days of incubation. After this time, when endogenous PRL levels become elevated (Day 16), exogenous oPRL no longer altered allantoic fluid volume or Cl-. Ovine PRL also stimulated Na+-K+-ATPase activity in the metanephros when embryos were treated before 14 days of incubation but did not stimulate the transport enzyme in mesonephros. Stimulation of metanephric Na+-K+-ATPase was a direct action of oPRL since this activity was also stimulated by the hormone in metanephros maintained in organ culture for 3 days. PRL did not stimulate Na+-K+-ATPase in organ-cultured mesonephros, and it failed to stimulate Na+-K+-ATPase in metanephros of juvenile chickens treated after hatching. Injection of AVP, a known contaminant of the NIH-oPRL used in these experiments, duplicated some, but not all actions of oPRL in the embryo. Like oPRL, AVP reduced the Cl- concentration of allantoic fluid, but AVP did not mimic the effect of oPRL in stimulation of metanephric Na+-K+-ATPase activity. Thus, oPRL preparations appear to possess osmoregulatory actions in the embryo which can be distinguished from actions attributable to the contaminant, ADH. Aldosterone injected prior to 16.5 days of incubation depressed activities of Na+-K+-ATPase and Mg2+-ATPase in mesonephros, but did not alter these enzyme activities in metanephros. The depressed enzyme activities induced by aldosterone in mesonephros may have been, in part, a toxic response to the hormone as control injections of cholesterol had comparable effects. On the other hand, aldosterone specifically stimulated Ca2+-dependent ATPase(s) and succinate dehydrogenase in metanephros. The three principal osmoregulatory hormones of adult birds, PRL, ADH, and aldosterone, seem to be active also during ontogeny of the avian embryo, with mesonephric and metanephric kidneys as target organs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23816/1/0000055.pd

Lipid composition and in vitro biosynthetic rates of neutral lipids and phosphatidylcholine in anterior and posterior chambers of the goldfish swimbladder

1. 1. Lipid composition was compared in anterior and posterior swimbladder and also in lavages of both chambers in the goldfish.2. 2. Anterior bladder contained more phosphatidylethanolamine and sphingomyelin than posterior chamber, but phosphatidylcholine contents were similar.3. 3. Cholesterol formed 17% of lipids in lavage-fluid in anterior chamber and 30% in posterior chamber. Lavage phospholipid contents in four pooled samples of each chamber were below detectable limits. Thus. surface-active phospholipids do not appear to be secreted by either chamber of goldfish swimbladder.4. 4. Uptake and incorporation of [14C]-acetate into total lipids, cholesterol and free fatty acids was greater in anterior than in posterior chamber. Rates of [3H]methylcholine incorporation into phosphatidylcholine were similar in both chambers.5. 5. Goldfish anterior and posterior swimbladder display differences in lipid composition and metabolism which may be related to functional specializations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24543/1/0000823.pd

What’s All the Racket? Comparing Physical Health Outcomes Between Pickleball and Tennis in Older Athletes

Background: Pickleball is rising in popularity, especially among older adults. Pickleball boasts psychological and physical benefits to aging athletes. Singles pickleball has been found to approximate brisk walking in metabolic equivalents (METs) at 4.1, while the METs level for singles tennis is 7.0-8.0. The physical health benefits of tennis are known to be positive while those of pickleball are still being explored. With objective differences in MET level it may be surmised that health outcomes might vary between the two sports. Purpose: The purpose of this study was to use the Senior Athlete Fitness Exam (SAFE) to quantify and compare the health characteristics of older pickleball athletes to older tennis athletes. Methods: Senior athletes who completed the SAFE at the National Senior Games between 2013 and 2019 and were exclusively registered to compete in pickleball or tennis were analyzed. Screening was conducted by trained personnel and included subtests for cardiovascular health, strength, mobility, flexibility, and balance. Demographic information and SAFE subtest results were compared between tennis and pickleball groups. Results: Significant differences were found between tennis and pickleball athletes in the categories of single leg balance with eyes open (p = 0.03), fast gait speed (p = 0.02), and shoulder range of motion (p \u3c 0.01). Pickleball players performed better than tennis in all significantly different outcome measures. Conclusion: Pickleball and tennis provide similar health benefits to older athletes, leaving more options for older adults interested in staying healthy. Previously reported intensity levels for pickleball may be underestimated

Precision Healthcare of Type 2 Diabetic Patients Through Implementation of Haptoglobin Genotyping

It is well-recognized that there is a need for medicine to migrate to a platform of delivering preventative care based on an individual's genetic make-up. The US National Research Council, the National Institute of Health and the American Heart Association all support the concept of utilizing genomic information to enhance the clinical management of patients. It is believed this type of precision healthcare will revolutionize health management. This current attitude of some of the most respected institutes in healthcare sets the stage for the utilization of the haptoglobin (Hp) genotype to guide precision management in type 2 diabetics (DM). There are three main Hp genotypes: 1-1, 2-1, 2-2. The Hp genotype has been studied extensively in (DM) and from the accumulated data it is clear that Hp should be considered in all DM patients as an additional independent cardiovascular disease (CVD) risk factor. In DM patients Hp2-2 generates five times increased risk of CVD compared to Hp1-1 and three times increased risk compared to Hp2-1. Data has also shown that carrying the Hp2-2 gene in DM compared to carrying an Hp1-1 genotype can increase the risk the microvascular complications of nephropathy and retinopathy. In addition, the Hp2-2 gene enhances post percutaneous coronary intervention (PCI) complications such as, in stent restenosis and need for additional revascularization during the first-year post PCI. Studies have demonstrated significant mitigation of CVD risk in Hp2-2 DM patients with administration of vitamin E and maintaining tight glycemic control. CVD is the leading cause of death and disability in DM as well-representing a huge financial burden. As such, evaluating the Hp genotype in DM patients can enhance the predictability and management of CVD risk

Ontogeny of embryonic chicken lung: Effects of pituitary gland, corticosterone, and other hormones upon pulmonary growth and synthesis of surfactant phospholipids

The actions of hormones on growth, cellular proliferation, and on synthetic rates of the major surfactant phospholipids, phosphatidylcholine (PC) and disaturated PC (DSPC), were studied in the lung of the chick embryo. Particular emphasis was placed on the effects of hypophysectomy, pituitary transplantation, and treatment with corticosterone (CORT). One study was concerned with hydrocortisone (HYCORT), estrogen (E2), thyroxine (T4), ovine prolactin (oPRL), and insulin. Hypophysectomy interfered with the normal gain in protein, the progressive dehydration of the embryonic lung, and also caused a reduction in the number of pulmonary cells on Days 16 and 18 of incubation. Absence of the pituitary gland diminished pulmonary PC by Day 16. Transplantation of one pituitary gland or exogenous CORT partially restored pulmonary phospholipid and PC (normalized per wet weight) in hypophysectomized (hypox) embryos. Transplantation also restored relative protein content in lungs of hypox individuals. Beyond this, transplantation was generally ineffective in reversing deficits of hypox individuals. All concentrations of CORT administered (30-100-300 [mu]g) reduced the rate of pulmonary cell division. The highest dose was toxic as judged by its capacity to cause cellular death. Treatment of intact chicken embryos with CORT or E2 for two days stimulated incorporation of [14C]choline into PC and DSPC (the most surface-active component of PC) in the lungs of Day 17 embryos. CORT, but not E2, stimulated DSPC synthesis when treatment was increased to 3 days. Other hormones tested (T4, oPRL, insulin, and HYCORT) had no effect upon the rate of incorporation of [14C]choline into PC or DSPC. These results indicate that during ontogeny the avian lung becomes sensitive to CORT, and possibly E2, prior to 16 days of incubation. CORT, in particular, acts both to trigger the prehatching stimulation of surfactant phospholipid synthesis, especially the vital DSPC fraction, and to slow the rate of pulmonary cellular division coincident with biochemical differentiation of the surfactant system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25095/1/0000527.pd