Effects of a Low-oestrogen Oral Contraceptive on Urinary Excretion of Luteinizing Hormone and Ovarian Steroids

The urinary gonadotrophin and ovarian steroid excretion pattern was studied in five women taking an oral contraceptive formulation consisting of mestranol 50 μg and norethisterone 1 mg. Both the pretreatment and post-treatment cycles were normal. The ovulatory peak of luteinizing hormone (LH) during the treatment cycles was uniformly suppressed, but LH continued to be excreted within the normal range. In one fifth of the treatment cycles there was a pronounced and sustained rise of oestrogen output in the absence of ovulation, and in many of the other treatment cycles oestrogen levels suggested that active ovarian steroidogenesis was taking place.     

Sexual Dimorphism in Urinary Angiotensinogen Excretion During Chronic Angiotensin II−Salt Hypertension

BackgroundThe intrarenal renin−angiotensin system contributes to hypertension by regulating sodium and water reabsorption throughout the nephron. Sex differences in the intrarenal components of the renin−angiotensin system have been involved in the greater incidence of high blood pressure and progression to kidney damage in males than females.ObjectiveThis study investigated whether there is a sex difference in the intrarenal gene expression and urinary excretion of angiotensinogen (AGT) during angiotensin II (Ang II)−dependent hypertension and high-salt (HS) diet.MethodsMale and female Sprague-Dawley rats were divided into 5 groups for each sex: Normal-salt control, HS diet (8% NaCl), Ang II−infused (80 ng/min), Ang II−infused plus HS diet, and Ang II−infused plus HS diet and treatment with the Ang II receptor blocker, candesartan (25 mg/L in the drinking water). Rats were evaluated for systolic blood pressure (SBP), kidney AGT mRNA expression, urinary AGT excretion, and proteinuria at different time points during a 14-day protocol.ResultsBoth male and female rats exhibited similar increases in urinary AGT, with increases in SBP during chronic Ang II infusion. HS diet greatly exacerbated the urinary AGT excretion in Ang II−infused rats; males had a 9-fold increase over Ang II alone and females had a 2.5-fold increase. Male rats displayed salt-sensitive SBP increases during Ang II infusion and HS diet, and female rats did not. In the kidney cortex, males displayed greater AGT gene expression than females during all treatments. During Ang II infusion, both sexes exhibited increases in AGT gene message compared with same-sex controls. In addition, HS diet combined with Ang II infusion exacerbated the proteinuria in both sexes. Concomitant Ang II receptor blocker treatment during Ang II infusion and HS diet decreased SBP and urinary AGT similarly in both sexes; however, the decrease in proteinuria was greater in the females.ConclusionDuring Ang II−dependent hypertension and HS diet, higher intrarenal renin-angiotensin system activation in males, as reflected by higher AGT gene expression and urinary excretion, indicates a mechanism for greater progression of high blood pressure and might explain the sex disparity in development of salt-sensitive hypertension.     

Urinary Excretion of C3 Antigen in Glomerulonephritis

C3 and fibrin degradation products (F.D.P.) have been measured in early morning urine samples from 38 normal people and 123 patients with glomerulonephritis. Normal urine contained less than 0·3 μg of either antigen per ml. C3 and F.D.P. were both detected in the urine of many patients with glomerulonephritis. Levels above 1 μg/ml were exceptional in patients with “minimal change,” and the highest excretion of both antigens occurred in mesangiocapillary glomerulonephritis, membranous nephropathy, and focal glomerulosclerosis.Both C3 and F.D.P. excretion showed considerable variation with time, with parellel fluctuations in the two antigens. These fluctuations did not depend on the total protein leakage and suggest that the complement and clotting sequence are closely related in these glomerular disorders.     

Effects of Oestrogen on Urinary Thyroxine Excretion

The day to day variation and the effects of oestrogen on the urinary excretion of thyroxine (T-4) were studied in euthyroid women and men. Serial urinary T-4 values over a period of 28 consecutive days were found to lie within relatively narrow limits except for a transient increase during menstruation in women. During oestrogen therapy urinary T-4 was unchanged, but an appreciable rise was seen after stopping oral ovulation inhibitors in women. A similar effect was seen in men after three days'' treatment with 20 μg/day of ethinyloestradiol. The increased urinary T-4 excretion on oestrogen withdrawal reached a maximum in one to three days. This response contrasted with that produced by phenytoin, a drug known to bind to thyroxine binding globulin, and which resulted in increased urinary T-4 excretion during the period that it was being administered.     

Urinary Sodium and Potassium Excretion in Fasting Obese Subjects

Data are presented on the urinary excretion of sodium and potassium in 40 obese patients subjected to therapeutic starvation. Two patterns of sodium loss were observed: either a uniform low-level loss or a fluctuating loss leading in some cases to marked sodium depletion. In three patients the response was a combination of these two patterns.     

Urinary Excretion of Nitric Oxide, Cyclic Gmp, and Catecholamines During Rest and Activity Period in Transgenic Hypertensive Rats

Dysregulation of the system of nitric oxide (NO)-cyclic 3',5'-guanosine monophosphate (cGMP) might be involved in the development of hypertension in transgenic hypertensive TGR(mREN2)27 (TGR) rats. The present study was performed to determine possible differences in the day-night pattern and the urinary excretion rates of NO and cGMP in TGR rats in comparison to normotensive Sprague-Dawley (SPRD) controls. In addition, the urinary excretion of creatinine and catecholamines was measured in both rat strains. The day-night excretion patterns of NO, cGMP, catecholamines, and creatinine were preserved in TGR rats. Urinary excretion of NO was significantly decreased in TGR rats, whereas cGMP, the second messenger of NO, was elevated in the transgenic animals. Catecholamines and creatinine excretion rates did not differ between the strains. In conclusion, data suggest that a reduced NO synthesis could contribute to the increased blood pressure in the severely hypertensive rats. However, these data make it unlikely that the disturbances in the nitric oxide-cGMP system and the sympathetic nervous system are mainly responsible for the inverse circadian blood pressure rhythm in TGR rats.     

Excretion of Urinary Casts after the Administration of Diuretics

The administration of ethacrynic acid and frusemide to healthy volunteers was regularly followed by the excretion of hyaline casts, without any concomitant proteinuria. Hydrochlorothiazide and chlorthalidone did not themselves induce cylindruria but augmented that provoked by acidifying agents. It was shown by the indirect immunofluorescence method that the casts were composed of uromucoid (Tamm-Horsfall mucoprotein), which is always present in the urine, usually in solution, and originates predominantly from the tubule cells of the ascending limb of Henle''s loop. The urinary excretion of Tamm-Horsfall mucoprotein was not increased after the administration of ethacrynic acid. This mucoprotein is precipitated and forms aggregates when the concentration of electrolytes increases and when the pH of the urine declines. The casts that appear in the urine after strenuous physical exertion are of essentially the same composition. Casts produced by patients with kidney diseases, on the other hand, contain various protein fractions derived from the blood as well as mucoprotein. Cylindruria occurring during diuretic therapy and physical exertion is of no pathological significance, and the diagnostic value of byaline casts is very much limited if their exact composition cannot be determined.     

Assessment of Urinary Iodine Excretion Among Normal Kuwaiti Adults

This study was performed to investigate the status of iodine intake among the Kuwaiti population and its effect on thyroid function. The study group was comprised of 139 females and 86 males with a mean age of 33 and 35 years, respectively. Urinary iodine excretion (UIE) and serum free T4 (FT4), thyrotropin hormone (TSH), antiperoxidase antibodies (anti-TPOAb), and antithyroglobulin antibodies (anti-TGAb) were determined. Median UIE was 148 µg/L (within the recommended level by the World Health Organization [WHO]). However, UIE levels of <100 and <50 µg/L were detected in both male and female groups, respectively. Serum levels of TSH and FT4 were normal for all except one of the participants who suffered from hyperthyroidism, possibly as a result of elevated iodine intake, which was reflected in an increased UIE of 590 µg/L. Elevated anti-TPOAb >75 IU/mL and anti-TGAb >150 IU/mL were detected in 15% and 34% of subjects; only 10% of them had elevated levels of both anti-TPOAb and anti-TGAb. Thus, based on the WHO recommendations, the iodine intake for the Kuwaiti population is adequate. However, it is recommended that a national study be conducted by the appropriate authority in order to eliminate any artifacts which may have appeared in this study.