[Aging and the endocrine system. Change of male sexual function by aging].
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Aging↗
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Body weight control practice as a cause of infertility.
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Adipose Tissue↗
Body weight and the initiation of puberty.
The onset and progression through the various stages of puberty are influenced by a number of factors (Fig. 2). In both animals and humans, the age of puberty appears to be related more to body weight than to chronologic age. Undernutrition and low body fat, or an altered ratio of lean mass to body fat, seem to delay the adolescent spurt and to retard the onset of menarche. According to Frisch, a minimum level of fatness (17% of body weight) is associated with menarche; however, a heavier minimum weight for height, representing an increased amount of body fat (22%), appears necessary for the onset and maintenance of regular menstrual cycles in girls over 16 years of age. This critical amount of body fat implies that a particular body composition, in addition to other environmental and psychosocial factors, is important in triggering and maintaining the pubertal process.
Adipose Tissue↗
The effect of RU486 administered during the proliferative and secretory phase of the cycle on the bleeding pattern, hormonal parameters and the endometrium.
Seventeen healthy women aged 24-45 years with regular menstrual periods, proven fertility and not using steroidal contraceptives or IUD were recruited for the study. The volunteers were followed during one control, one treatment and one follow-up cycle. Daily morning urine samples were obtained during the control and the treatment cycle. The samples were analysed with regard to pregnanediol glucuronide (P2-G), oestrone glucuronide (E1-G), oestradiol (E2), progesterone (P4), LH and creatinine. During the entire 3-month study the subjects kept a record of uterine bleeding and side effects. The subjects received 50 mg RU486 daily either on cycle days 7-10 (n = 7) or on cycle days 20-23 (n = 10). An endometrial biopsy was taken on cycle day 10 in the first group and on cycle days 21-28 in the second group of patients. Treatment during the proliferative phase caused significant prolongation of the cycle length due to a delay of the oestrogen and LH surge. However, once the oestrogen concentration started to increase, the remaining part of the cycle was normal. The length of the follow-up cycle was similar to that of the control cycle. The morphology of the endometrium did not differ from control samples taken from untreated women at the same time of the cycle. All ovulating women (n = 9) treated in the mid-luteal phase started to bleed on the 3rd to 4th day of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
An assessment of the dual-analyte enzyme immunoassay for ovulation timing.
In a search for simpler, more efficient methods of monitoring ovulatory function, either to assist in the investigation of the infertile couple or for contraceptive or fertility control purposes, a number of new methods have been developed. One of these, the OVEIA dual-analyte system is now available for laboratory use. The principle behind the system is the simultaneous measurement of urinary oestrone-glucuronide and pregnanediol-glucuronide. The resultant signal is quantified using an enzymatic photometric endpoint denoted by the relative absorbance (RA%). The application of the OVEIA system to the monitoring of urine samples over the periovulatory period in ovulatory and non-ovulatory cycles from regularly cycling but infertile women is described and the changes in RA% compared with synchronously measured changes in plasma LH and plasma oestradiol concentrations, salivary progesterone profiles and measurements of follicular volume. It is concluded that the OVEIA system is simple and quick to perform and the results obtained compare reasonably well with equivalent direct and indirect indicators of impending ovulation (e.g. increasing plasma oestradiol concentrations or changes in the volume of the follicle). However, as is the case with other endocrine methods, definitive information about the presence or absence of follicular rupture cannot be obtained.
Adult↗
Ovulatory dysfunction during continuous administration of low-dose levonorgestrel by subdermal implants.
OBJECTIVE: To study the endocrinologic profile of regularly menstruating users of levonorgestrel subdermal implants. DESIGN: Observational, prospective, case-controlled comparative study. SETTING: The Family Planning Clinic of PROFAMILIA, in Santo Domingo, Dominican Republic. PATIENTS, PARTICIPANTS: Thirty one regularly cycling Norplant users and 12 nonhormonal contraceptors who volunteered to participate. INTERVENTIONS: Norplant contraceptive implants were inserted in 31 subjects between 13 and 77 months before this study. MAIN OUTCOME MEASURES: Follicle-stimulating hormone, luteinizing hormone, estradiol (E2), and progesterone (P) were serially assayed for one menstrual cycle. RESULTS: Almost half of the cycles among Norplant users were anovulatory; all the rest (55%) had some form of dysfunction: diminished gonadotropin surge, luteal phase insufficiency (low P levels and shortened luteal phase), and E2 profiles different from normal controls. CONCLUSIONS: Anovulation is clearly one of the main mechanisms of action of Norplant, but even in presumptive ovulatory cycles, the dysfunctions described possibly contribute to the high contraceptive effectiveness of Norplant.
Adult↗
Immunological and physiological responses to whole-body hyperthermia.
Current information on the effect of systemic hyperthermia on the host-tumor immunologic response was reviewed. Changes in physiology caused by whole-body heat are described in a review of current studies at the National Cancer Institute and others, with particular regard to cardiovascular, endocrine, and nervous system changes with heat. The importance of these heat-affected alterations of physiology and immunology on chemotherapy and radiotherapy administration is discussed.
Animals↗
Interleukin-1 and the effects of cyclooxygenase inhibitors on its biological activities.
Interleukin-1 (IL-1) is a polypeptide produced following infection, injury, or antigenic challenge. Although the macrophage is a primary source of IL-1, epidermal, epithelial, lymphoid, and vascular tissues synthesize IL-1. When IL-1 gains access to the circulation, it induces a broad spectrum of systemic changes in physiologic, neurologic, metabolic, hematologic, and endocrine systems. However, because IL-1 lacks a signal peptide, a considerable amount of the IL-1 synthesized may remain associated with the cell and particularly as part of the plasma membrane where it may participate in lymphocyte activation and mesenchymal tissue remodeling. Two gene products code for IL-1: IL-1-beta and IL-1-alpha. The spectrum of biological activities of IL-1 are induced by both forms and receptors for IL-1 recognize both forms. The most consistent property of IL-1 is upregulation of cellular metabolism and increased expression of several genes coding for biologically active molecules. IL-1 is a highly inflammatory molecule and stimulates the production of arachidonic acid metabolites, most consistently, prostaglandin E. IL-1 also acts synergistically with other cytokines, particularly tumor necrosis factor. Some of the multiple biological effects of IL-1 and tumor necrosis factor are prevented by cyclooxygenase inhibitors whereas others are unaffected. Given the widespread use of cyclooxygenase inhibitors, understanding their effect on IL-1 and tumor necrosis factor action is important in several disease models.
Animals↗
The pineal gland and mammalian photoperiodism.
The mammalian pineal gland appears to be a major endocrine component in the regulation of photoperiodic responses. The circadian pattern of secretion of the pineal hormone, melatonin, is regulated by the nervous system. Changes in photoperiod, acting via the nervous system, alter the temporal pattern of melatonin secretion. The changes in secretion pattern convey information about daylength from neural components of the circadian system to the reproductive system, and probably to other physiological systems.
Animals↗
Cells of the fetomaternal interface: their role in the maintenance of viviparous pregnancy.
An immune system capable of discriminating between self and nonself evolved in nature long before the appearance of the viviparous mode of pregnancy, which brings maternal cells into a direct physical contact with genetically disparate cells of fetal origin. In the hemochorial type of placentation, the former include cells of the maternal immune system. This article briefly reviews the possible mechanisms that may protect the semiallogeneic conceptus in nature, with special reference to the role of the cells at the fetomaternal interface. We also present some new data on the antigenicity of pre- and postimplantation trophoblast cells and the immunobiology of decidual cells. Systemic changes in the maternal immune system appear to represent homeostatic responses to the presence of a semiallogeneic conceptus, unrelated to its protection; mechanisms for this protection must reside locally at the fetomaternal interface. We find that the lack of immunogenicity of the outer (trophoblast) cells of the preimplantation blastocyst can be explained by a transient disappearance of the major histocompatibility (MHC) antigens on their cell surface. However, following implantation and the formation of the placenta, class 1 MHC antigens reappear on certain classes of trophoblast cells, i.e., labyrinthine and spongiotrophoblast cells of the murine placenta. Similarly, cytotrophoblast cells of the early human placenta exhibit the presence of class 1 MHC antigens. An absence of class 2 MHC antigens despite the presence of class 1 antigens cannot entirely explain the lack of trophoblast immunogenicity. A local immunosuppression mediated by trophoblast cells themselves as well as maternal cells of hemopoietic origin in the decidua remain as a strong possibility. Typical decidual cells appear to play a central role in the maintenance of pregnancy because of their numerous functions: nutritive, endocrine, and immunoregulatory. Our studies reveal that they are descendants of bone-marrow-derived precursors, have unique surface markers recognizable with monoclonal antibodies nonreactive with other hemopoietic cell lineages, and have the ability to abrogate mixed lymphocyte reactions in vitro in a genetically unrestricted manner. Further studies directed at the cells of the fetomaternal interface should provide a better insight into the mode of survival of the nature's most commonplace allograft.
Animals↗
Metabolic changes in women using a long-acting monthly oral contraceptive and return of ovulation on discontinuation.
Metabolic changes were investigated in two groups of women using oral contraceptives for 5 to 16 years. Blood samples were taken during the last cycle of oral contraceptive use and three months post-treatment. One group had used a monthly oral contraceptive (MOC, 3mg quinestrol and 10mg 16-methylene chlormadinone acetate) and the second group a daily oral contraceptive (DOC, 35 micrograms ethynylestradiol and 0.625 mg norethisterone). During treatment there were increases in serum total cholesterol and triglycerides but not HDL-C, in plasma total cortisol but not in renin activity, angiotensin II or urinary free cortisol excretion, in hemoglobin and some coagulation factors but not Factor X or antithrombin III, platelet function or fibrinolysis. The area under the blood glucose concentration-time curve, but not that for serum insulin, was slightly increased and there was no change in fasting blood sugar concentrations. All metabolic parameters, except plasma cortisol, which had shown an increase on treatment, had decreased to control levels within 3 months. Ovulation returned promptly in all women, the mean time being 70 days for Group MOC and 44 days for Group DOC. Thus, in spite of the long duration of use of the oral contraceptives, metabolic changes were minor.
Adult↗
Serum and endometrial sodium and potassium levels with inert and copper-containing IUCDs and relation to serum steroid levels.
Serum and endometrial sodium (Na) and potassium (K) levels and serum estradiol, progesterone, testosterone and cortisol were measured in the mid-follicular and mid-luteal phases of the menstrual cycle in 20 Lippes loop and 20 CuT-200 IUCD users and 20 matched controls. Na and K were measured by atomic absorption spectrophotometry, while serum steroids were measured by RIA. Regarding steroids, the only significant difference between the three groups was a significantly lower mean mid-luteal serum estradiol in CuT-200 IUCD users compared to Lippes loop users (p less than 0.05). Regarding sodium in the control group, there was significantly lower mean mid-luteal serum and endometrial Na (p less than 0.01) that was not found in both groups of IUCD users. In the mid-follicular phase, there was significantly higher mean serum Na in both Lippes loop and CuT-200 groups compared to controls (p less than 0.05). Mean endometrial Na showed no significant difference between the three groups in both phases of the menstrual cycle. Regarding potassium in the control group, there was significantly lower mean levels in the mid-luteal-phase of the cycle (p less than 0.01) that was not seen with both groups of IUCD users. Serum K showed no significant difference in the three groups in both phases of the menstrual cycle. Endometrial K showed a significantly higher mean level in both Lippes loop and CuT-200 IUCD users compared to controls in the mid-luteal (p less than 0.01), but not in the mid-follicular phases of the cycle.
Analysis of Variance↗
Antispermatogenic action of gossypol in men.
Twelve Brazilian men were treated with gossypol for 1 year. The treatment schedule consisted of oral administration of 20 mg gossypol daily for 4 months, followed by a maintenance dose of 20 mg on alternate days (3 days a week), totaling 60 mg weekly for 8 months. Ten men became azoospermic at the end of the fourth month of treatment, and the two others developed marked oligospermia with necrospermia. Except for one man who complained of transient listlessness and fatigue, the subjects reported no side effects during treatment. No changes in libido or potency were reported, and plasma testosterone remained unchanged. Blood chemistry values, which included complete blood cell count, cholesterol, glucose, triglycerides, acid phosphatase, urea, transaminases, sodium, and potassium, were not changed significantly during treatment. The response of the pituitary to gonadotropin-releasing hormone stimulation and the response of the testis to gonadotropin stimulation appeared normal in men treated with gossypol. After treatment, the sperm counts reverted to essentially normal levels in 8 of 12 men. In four men, azoospermia continued 1 year after discontinuation of gossypol treatment. Retrograde phlebography carried out in three of the four men who remained azoospermic after discontinuation of therapy revealed subclinical varicocele.
Adult↗
The systemic response of the traumatized patient: an overview.
A metabolic conflict occurs between increased production of easily used substrates and inhibition of their metabolism in any injured animal. The terms ebb and flow describe the dwindling and rising tides of such activity. The ebb may last 24 to 72 hours; the flow is usually over within two weeks but may last up to eight weeks or longer in more severe cases. The ebb phase corresponds to the traumatic and initial post-traumatic period when there usually is adequate substrate (oxygen, glucose, fatty acid) to meet the diminished demand of the tissues. The flow phase is the period of convalescence. The object of the organism's initial defense following injury seems to stabilize the situation during the ebb phase (preservation of the internal milieu). The longer the ebb phase can be maintained and the more substrates that can be conserved, the more likely the animal will recover during the flow phase. The ebb phase is set in motion by an injury such as hemorrhage, burns, fractures, soft tissue damage by crushing sepsis, or diarrhea. After the ebb phase, a variable, integrated response of nervous, endocrine, and metabolic systems begins, which compromises normal function to achieve specific survival objectives (that is, protection, stabilization and adaptation). Systemic changes (such as tissue catabolism) devoted to caloric needs and local growth (that is, wound repair) are all directed at the ultimate objective of survival.
Animals↗
Endocrine problems in the menopause.
The climacteric is an interval characterized by a multitude of physiologic, psychologic, and sociologic alterations that result in an individual's adaptation to life beyond reproduction. The common denominator of the physiologic changes is the loss of functional ovarian follicles and their ability to produce estradiol. The relative estrogen deficiency results in a myriad of systemic changes, some of which in themselves may impair the quality of life or be life-threatening. Estrogen replacement therapy is effective in alleviating some of these changes, including osteoporosis, vasomotor symptoms, and genital atrophy. This treatment, however, confers additional risks, endometrial adenocarcinoma being the one of greatest concern. This risk can be reduced by carefully selecting patients to be treated, closely following them, minimizing the duration and amount of exposure, and adding a progestin to the regimen. It is hoped that the risk of endometrial cancer and other adverse reactions associated with estrogen use can be further reduced when more data regarding optimum dosage and choice of agents are available.
Adenocarcinoma↗
Changing hypothalamopituitary function: its role in aging of the female reproductive system.
Changes in female reproductive function occur relatively early during the life span in many mammalian species. Therefore, this physiological system is an excellent model system in which to study the effects of age on specific endocrine relationships since changes occur prior to the occurrence of multiple pathologies associated with later stages of aging. Data from several laboratories suggest that changes in hypothalamic, pituitary and ovarian function may contribute to age-related deterioration of fertility in females. We will focus our attention on the role of hypothalamic changes in the cascade of events that eventually lead to acyclicity and infertility. Data suggest that changes in the diurnal rhythmicity of catecholaminergic neurotransmitters and their receptors occur during middle age. These changes may regulate the pattern of release of GnRH since alterations in the pulsatile pattern of LH secretion also become detectable at this age. Some age-related changes in hypothalamic and pituitary function are not irreversible or absolutely determined. Instead it appears that the ovarian steroidal milieu modulates the rate of aging of several aspects of hypothalamohypophysial function. In summary, changes in hypothalamic and pituitary function appear to contribute to the aging of the female reproductive system.
Aging↗
Local hormonal factors (intracrine, autocrine, and paracrine) in hypertension.
Vasoactive hormones acting as endocrine, neuroendocrine, or local hormonal systems (intracrine, autocrine, and paracrine) are an important component of the many factors that regulate blood pressure. Hypertension may be the result of an alteration in the balance between vasodepressor and vasopressor hormonal systems. Changes in this balance could be due to genetic factors such as mutations in one of the genes of the vasoactive system or environmental factors that alter the synthesis and release of one or more vasoactive hormones. Endocrine and neuroendocrine vasopressor hormonal systems, such as the renin-angiotensin system and catecholamines, play a well-established and important role in the regulation of blood pressure and the pathogenesis of some secondary forms of hypertension. The blockade of such systems has already resulted in effective antihypertensive treatment. The role of local hormonal systems is less well established; however, recent evidence suggests they also play an important role in the regulation of blood pressure and the pathogenesis of hypertension. Some vasopressor hormonal systems, such as the renin-angiotensin system, can act as both endocrine or local hormonal systems. Work using transgenic rats harboring the mouse Ren-2 gene has conclusively demonstrated that the renin-angiotensin system, acting as a local hormonal system, has the capability to cause severe hypertension. Whether this model of experimental hypertension mimics any type of human hypertension is not known. Vasodepressor hormones such as kinins, prostaglandins, and endothelium-derived relaxing factor (EDRF) act mainly as local hormonal systems, with the notable exception of atrial natriuretic factor, which may act as both an endocrine and a local hormone. The tissue kallikrein-kinin system, acting either directly or via paracrine eicosanoids or EDRF, participates in local regulation of the circulation, renal function, and the acute antihypertensive effect of angiotensin converting enzyme inhibitors. A restriction fragment length polymorphism (RFLP) that distinguishes the kallikrein gene family of a strain of spontaneously hypertensive rats (SHR) from normotensive Brown Norway rats has been identified. In a set of 32 recombinant inbred strains derived from these SHR and Brown Norway strains, the RFLP marking the kallikrein gene family of SHR cosegregated with an increase in blood pressure. Also, in a study of Utah families it was found that a dominant-allele kallikrein gene expressed as high urinary kallikrein excretion was associated with a decreased risk of essential hypertension. In conclusion, vasopressor and vasodepressor hormones, acting not only as endocrine but also as local hormones, play an important role in the regulation of blood pressure and the pathogenesis of hypertension.(ABSTRACT TRUNCATED AT 400 WORDS)
Angiotensin II↗
[Chronic toxicity study on difluprednate in dogs].
The chronic toxicity of a new topical glucocorticoid, difluprednate (DFBA) was studied in Beagle dogs. DFBA ointment (0.05%) was percutaneously treated to the back of dogs at daily doses of 125, 12.5 and 1.25 micrograms/kg for 6 months. The local effects of DFBA In the treated area, thinning of the skin and inhibition of the fur-growth were observed with scale and erythema. The skin showed histological atrophy of the epidermis, a decrease of the adipose tissue and atrophy of the adnexa. These changes returned to normal after the 2-month withdrawal period. The systemic effects of DFBA In the 125 micrograms/kg group, the following changes were observed, although neither death nor severe symptoms occurred: General observations were seen an increase of water intake and urinary volume. A decrease of lymphocytes and eosinophils, and an increase of neutrophils were observed in the hematological examination. There were high sodium and low potassium levels, and an increase of alkaline phosphatase and gamma-glutamyltranspeptidase activities in the biochemical examination. The organ weights showed a decrease of the thymus, adrenals, prostate and ovaries, and an increase of the liver and kidney. An atrophy of the lymphatic tissues and adrenal cortex, retardation of the sexual maturation, glycogen deposit in the hepatic cells, slight degeneration of the renal tubuli, and slight thinning of the sternum and non-treated skin were noted in the pathological examination. These changes returned to normal after the 2-month withdrawal period. In the 12.5 micrograms/kg group, the atrophic changes in the thymus, adrenal and non-treated skin appeared slight. In the 1.25 micrograms/kg group, no changes were found. Conclusively, all the local and systemic changes observed by DFBA in this study were due to the already known pharmacological effects of glucocorticoids. It is considered that a 12.5 micrograms/kg dosage is similar to a non-effect dose.
Animals↗