Repeated acute or chronic exposure to a particular stress results in adaptation whereby the hypothalamopituitary adrenal (HPA) axis becomes less responsive subsequent continued that stress. To investigate adaptive changes occur HPA response humans, we studied effect of exercise on basal activity six highly trained male ultramarathon athletes and healthy controls matched for body mass index. After 3-5 d abstention from intense physical activity, subjects were admitted metabolic study ward at...

SUMMARY The excretion of follicle stimulating hormone (FSH), luteinizing (LH), oestrogens and pregnanediol was measured in weekly urine samples collected for 14–87 weeks (median, 43 weeks) from thirty‐one perimenopausal women aged 36–55 years 50 years). results were compared with those found twenty‐two postmenopausal 55·4 ± 5·4 (mean SD), twenty premenopausal 44·4 3·4 regular, ovulatory, menstrual cycles. Women classed as had a recent history irregular cycles following regular cyclicity....

We have used the technique which we developed for collecting pituitary venous blood from conscious, undisturbed horses to study effect of acute vigorous exercise on secretion CRF, arginine vasopressin (AVP) and ACTH. Pituitary (pit) was collected every 1–5 min nine trained racehorses at rest in stable. The then trotted quietly 10 min, after they galloped as fast possible 4–6 before returning stable where sampling continued. In Exp 1 (n = 5) no samples were taken during exercise, whereas 2...

The effect of confectionery liquorice on electrolyte status and the renin-angiotensin-aldosterone (RAA) axis was studied in 14 healthy volunteers. They ate daily doses 100 g or 200 (equivalent to 0-7-1-4 glycyrrhizinic acid) for one four weeks. Plasma potassium concentrations fell by over 0-3 mmol/l 11 people, including who had be withdrawn from study because hypokalaemia. One more values RAA axis, especially plasma renin activity urinary aldosterone concentrations, were considerably...

Abstract C 4 photosynthesis is used by the most productive plants on planet, and compared with ancestral 3 pathway, it confers a 50% increase in efficiency 1 . In more than 60 lineages, CO 2 fixation compartmentalized between tissues, bundle-sheath cells become photosynthetically activated How bundle sheath acquires this alternate identity that allows efficient unclear. Here we show changes to gene expression leaves are associated gain of pre-existing cis -code found leaf. From...

Summary OBJECTIVES We compared the responses of stress hormones, Cortisol, ACTH, vasopressin (AVP), corticotrophin releasing hormone (CRH) and catecholamines to elective conventional laparoscopic cholecystectomy. DESIGN A right upper quadrant transverse incision was used for cholecystectomy, four 1–2‐cm incisions procedure (for insertion surgical instruments, diathermy, fibreoptic telescope light source, carbon dioxide insufflation). Blood sampled immediately prior premedication (temazepam),...

OBJECTIVE The ob gene product, leptin, is considered to be a marker of adipose tissue mass and possible homeostatic regulator body mass. Our objective was examine the effect GH replacement on stores leptin in adult hypopituitarism. SUBJECTS Twenty adults, mean age 47 years (range 20–69) with proven deficiency were randomly allocated either (up 0.25 U/kg/week daily doses) or placebo for 3 months before cross‐over opposite treatment. MEASUREMENTS Body composition measured by dual‐energy X‐ray...

Plasma ACTH, arginine vasopressin (AVP), and catecholamines were measured at 5-min intervals in the pituitary venous effluent of unanesthetized horse. Pulses ACTH AVP found to be surprisingly brief (usually less than 10–min duration) frequent (averaging between 15–25 min). A highly significant relationship changes concentration these two hormones was demonstrated (P > 0.0002) both rest after a mild hypoglycemic stimulus. Although there also correlation 0.005) simultaneous plasma values pulse...

ABSTRACT A non-surgical, non-stressful technique was used for collection of pituitary venous blood from five conscious horses every minute two 10-min periods before and during isolation the herd, which caused a predictable, yet humane physiological, emotional stress. Pituitary also sampled 5 min approximately 90-min after isolation, while jugular 15 throughout experiment. During all became agitated, hyperventilating sweating. Packed red cell volume increased, as did concentrations adrenaline...

1. Plasma aldosterone concentration and urine excretion were studied before during sustained diuresis in six patients with gross congestive heart failure, under conditions of fixed sodium potassium intake strict control body posture. Simultaneous measurements plasma renin activity, corticotrophin electrolytes made to assess the relative importance these factors regulation secretion treatment failure. 2. During pre-treatment phase levels normal or raised, but acute fell unmeasurable most...

Summary BACKGROUND Abnormal baseline hypothalamic‐pituitary‐adrenal axis function and dexamethasone suppressibility seen in withdrawing alcoholics returns to normal on abstinence, but some studies report blunting of the ACTH response CRH persisting during early abstinence phase. Reduced central levels endogenous oplold peptides have been postulated an aetiological role In alcohol addiction. AIMS To evaluate a group recently abstinent using basal hormone data, naloxone (an receptor...

SUMMARY The excretion of FSH, LH, oestrogens and pregnanediol was monitored once weekly in urine samples collected from eight peri‐menopausal women aged 44–55 years (median, 52 years). Observations were commenced between 5 15 weeks before the menopause continued for 22–30 after final menstruation. Amenorrhoea > 2 duration association with a persistent elevation gonadotrophin output considered proof post‐menopausal state. No clear hormonal change occurred at time menopause. During...

The plasma ACTH response to corticotrophin releasing factor (CRF) was studied in seven normal individuals. Five subjects were restudied following 4 d of salt restriction which resulted raised endogenous angiotensin II secretion. In a third experiment six given CRF pre-infusion hypertonic saline significantly increased vasopressin (AVP) levels. We unable demonstrate that high AII levels associated with significant change the or cortisol responses CRF. However there an almost three-fold...

Plasma ACTH and cortisol profiles were studied over 24 h in five Addisonian patients maintained good health by conventional gluco- mineralocorticoid treatment. Patients received their usual treatment (15--30 mg daily) divided doses at 08.00 16.00 hours. concentrations differed from those of control subjects being higher hours-noon 17.00-18.00 hours unmeasurable (less than 20 nmol/l) during the period active secretion (03.00-08.00 hours) observed normal subjects. Peak plasma levels (618-...

The blood sugar, plasma cortisol and immunoreactive corticotrophin (ACTH) responses to insulin-induced hypoglycemia were analyzed in detail 9 individuals without evidence of pituitary disease 6 patients with hypopituitarism. In all the control subjects, ACTH levels more than trebled reach a maximum 45 min after insulin injection. response occurred 15–45 peak was prolonged. However, magnitude response, relative resting levels, greater. above time-response relationships may be altered...

The brief (60-min) infusion of a small amount (1.25 mug) ACTH into 7 normal subjects on an unrestricted sodium intake resulted in vigorous plasma aldosterone response each case. This finding suggests that physiologic fluctuations may significantly alter secretion man.

We wished to determine whether the increased ACTH during prolonged exercise was associated with changes in peripheral corticotropin-releasing hormone (CRH) and/or arginine vasopressin (AVP). Six male triathletes were studied exercise: 1 h at 70% maximal oxygen consumption, followed by progressively increasing work rates until exhaustion. Data obtained session compared a nonexercise control session. Venous blood sampled over 2-h period for cortisol, ACTH, CRH, AVP, renin, glucose, and plasma...

Summary. objective To evaluate the hypothalamo‐pitultary‐adrenal (HPA) response to both mild and Intense exercise. design Maximum oxygen consumption (Vo 2 max.) was Initially determined. Exercise 20% (mild) 90% (Intense) Vo max. undertaken in random order. Subjects were exercised over a 5‐minute period required level of Intensity, which maintained for further 10 minutes. subjects Six trained male athletes. measurements Brachial vein blood sampled before at intervals during after exercise...

First morning urine samples were collected from both menstruant and post-menopausal women stored at −25 °C. Immunoreactive FSH disappeared these ( t ½ = 30 days), ultimately stabilizing about 20% of the initial value. The loss was more rapid −20 °C less −55 +4°C. LH also lost frozen urine, but slowly than FSH. addition glycerol to (0·52 mol/l) prevented immunoreactive for least 105 days.