Measurement of the volume of extracellular water (ECW) was performed simultaneously with determinations of glomerular filtration rate (GFR) and renal plasma flow (RPF) in 12 hypophysectomized patients (five cases of metastatic mammary carcinoma and seven diabetic subjects) and in 13 cases of acromegaly. Thirteen normal subjects served as controls. ECW was estimated from the volume of distribution of inulin, GFR and RPF from the renal clearances of inulin and para-aminohippurate, respectively. In the acromegalic group, an increased GFR and RPF was found together with an increased ECW, confirming earlier observations. In the hypophysectomized patients (who were all on cortisone replacement therapy), GFR and RPF were markedly decreased. However, the reduction in GFR and RPF was not associated with any significant changes in ECW.

Intestinal transit was measured by following a radioisotope capsule through the gut. The transit in 16 elderly patients with chronic constipation was compared with that in 16 patients of the same age and with 10 healthy younger people without constipation. Although the constipated patients generally had a slower total transit time through the gut, some old and young people without constipation also showed a slow total transit. Constipated patients had a significantly slower transit only through the rectosigmoidal part of the colon. It is also suggested that old age per se does not imply an increased transit time.

Measurements of glomerular filtration rate (GFR) and renal plasma flow (RPF) were performed in close connection with roentgenographic estimation of kidney size, before and after hypophysectomy, in 10 patients (four cases of metastatic mammary carcinoma, five cases of diabetic retinopathy and one case of acromegaly). Hypophysectomy was regularly followed by a decrease in GFR and RPF. In most cases, a reduction in the roentgenographic kidney size was also observed. However, the changes in the roentgenographic kidney size and calculated kidney weight after hypophysectomy were smaller and occurred at a slower rate than the alterations in GFR and RPF. The results favour the view that, primarily, the decrease in GFR and RPF following hypophysectomy is essentially functional rather than due to a reduced kidney mass.

Transit time, as estimated from the passage through the gut of an isotope (131I)-containing capsule, was studied in 10 constipated, geriatric in-patients on a bulk laxative regimen and during treatment with wheat bran. The patients received a conventional bulk laxative (Vi-Siblin, 6 g twice daily) during a period of 8 weeks. The bulk laxative was then replaced by bran (10 g twice daily) during the following 8-week period. Measurements of transit time were taken after 4 and 6 weeks on each regimen. The mean transit time was 126 h for the bulk laxative regimen and 89 h for the bran treatment, the difference being statistically significant. The decrease in transit time for the bran treatment was essentially due to a faster passage through the rectosigmoid part of the bowel. Less additional laxative therapy was needed during bran treatment than during the bulk laxative treatment. The favourable properties of bran may tentatively be explained by the effects remaining in the distal part of the colon. A slight but significant lowering of the serum calcium level and a significant increase of the total iron-binding capacity of the serum were found after 7 weeks of bran administration, whereas no change was observed after 42 weeks. No significant change was demonstrated in serum iron during bran treatment.

Glomerular filtration rate (GFR) and renal plasma flow (RPF), as measured by clearances of inulin and para-aminohippuric acid, were studied before and after hypophysectomy in 23 patients (nine cases of metastatic mammary carcinoma, nine cases of diabetes mellitus with retinopathy, and five cases of acromegaly). In 12 of the patients, the maximal rate of tubular excretion of para-aminohippuric acid (TmPAH) was also studied. All subjects developed evidence of depressed adrenocortical function after hypophysectomy and were on replacement therapy with cortisone (17,21-dihydroxy-pregn-4-ene-3,11,20-trione) at the time of the postoperative studies. In four cases, postoperative hypothyroidism was not demonstrated. In all patients, GFR and RPF decreased after hypophysectomy and this reduction was present within four to eight weeks after surgery, when the first postoperative study was usually performed. In additional studies, at different intervals after hypophysectomy there were, on the whole, only minor further changes in GFR and RPF. Thyroid therapy increased GFR and RPF in the hypophysectomized patients but did not raise the values to the preoperative level. Following hypophysectomy TmPAH decreased in nine of the 12 patients studied. Thyroid therapy did not regularly increase the Tm values.