Glycosaminoglycans of the rat renomedullary interstitium: ultrastructural and biochemical observations.

The rat renal papillary interstitum which contains abundant proteoglycans is a unique area important in renal function. These proteoglycans were studied ultrastructurally by ruthenium red fixation and staining and phosphate-buffered fixation before and after enzyme digestion. A tissue culture of rat renomedullary interstitial cells, the predominant cell of the renal papillary interstitum, was studied for its ability to synthesize proteoglycans and the proteoglycans were then analyzed.

B2 bradykinin receptor-like binding in rat renomedullary interstitial cells.

A particulate fraction from cultured rat renomedullary interstitial cells (RRIC) was prepared for bradykinin (BK) binding studies. Incubation of three radiolabeled BK analogs, [125I-Tyr1]kallidin, [125I-Tyr5]-BK, and [125I-Tyr8]-BK, with the particulate fraction resulted in degradation of these peptides. Assay conditions which prevented hydrolysis of these radiolabeled kinins were determined.

The morphology and antihypertensive effect of renomedullary interstitial cells derived from Dahl sensitive and resistant rats.

The renomedullary interstitial cell (RIC) has been implicated in the antihypertensive action of the kidney. This cell has been isolated in tissue culture and shown to have an antihypertensive action in several models of experimental hypertension. Morphometric studies of RIC in vivo from Dahl rats sensitive and resistant to the hypertensive effects of high-salt diets indicate major differences between the RICs.

Juxtaglomerular cells grown as monolayer cell culture contain renin, angiotensin I-converting enzyme, and angiotensin I and II/III.

A monolayer cell culture of juxtaglomerular cells (JGC) was derived from the renal cortex of neonatal rats. The JGC had the characteristics of those within the kidney, including peripheral dense bodies and myofibrils indicating a smooth muscle origin; rough ER containing fluffy material consistent with protein synthesis; a prominent Golgi apparatus for packaging granules, and granules having the characteristics of secretory granules and lysosomes. Transplants of the cultured cells into syngeneic recipients survived for 2 weeks or longer and retained the features of JGC.

Cultured juxtaglomerular cells cause hypertension by secreting angiotensin.

Cultured JGC contain renin, angiotensin I, angiotensin I-converting enzyme, angiotensin II, and, by implication, the entire RAS. JGC, as transplants, appear to secrete angiotensin II/III directly into the bloodstream to cause hypertension when the renal mass is reduced. There are two main phases of the hypertensive state, an angiotensin-dependent developmental phase and a non-angiotensin-dependent maintenance phase.

Comparative effects of sulfones and rifampin on growth of Mycobacterium lepraemurium in macrophage diffusion chamber cultures.

A cell-impermeable diffusion chamber technique has been developed that lends itself to growth studies of Mycobacterium lepraemurium. This technique, in which the organism grows within macrophage cultures inside the chambers that are maintained on monolayer cultures of macrophages, provides a method for a strict in vitro evaluation of antileprosy drugs without the influence of a multiplicity of host factors. This system was used to compare the effect of three sulfone derivatives and rifampin on the growth of M.

Reversal of hypertension by transplants and lipid extracts of cultured renomedullary interstitial cells.

Transplants and lipid extracts of the same monolayer tissue culture of renomedullary interstitial cells from murine renal medulla exerted a similar antihypertensive action in rats having hypertension of the sodium-volume-dependent-type. The antihypertensive action resembled that caused by lipid extracts of rabbit renal medulla and extracts of lapine renomedullary interstitial cells grown in tissue culture. The recession of the arterial pressure of the hypertensive animals usually occurred slowly and steadily to a maximum within 6 to 12 hours.

Anti-hypertensive lipid tissue from culture of renomedullary interstitial cells of the rat.

1. Allogenic transplants of cultured renomedullary interstitial cells exert a powerful anti-hypertensive action. The blood pressure of hypertensive animals usually drops slowly over 8-12 h whereas the pulse is unchanged or reduced.

Functional-morphological correlates of renomedullary interstitial cells.

1. Indomethacin treatment of renomedullary interstitial cells (RIC) causes a marked increase in number and size of their lipid droplets. The anti-hypertensive function is retained.

Evaluation of a red cell agglutination test for detection of Australia antigen (HG Ag).

An investigational red cell agglutination (RCA) test was evaluated for sensitivity in detecting and titering hepatitis B antigen (HB Ag) in comparison with two counterelectrophoresis (CEP) systems and a solid-phase radioimmunoassay (RIA). The RCA procedure was found to be significantly more sensitive than the CEP methods and compares favorably in sensitivity with the solid-phase RIA, detecting even lower concentrations of the HB Ag. Since the RCA test can be completed in 2 to 3 h and requires relatively inexpensive equipment, it offers a highly sensitive and rapid procedure suitable for use in blood banks to screen donors or detect low levels of antigen in serum of patients.

Growth of Mycobacterium lepraemurium in Cell-Impermeable Diffusion Chambers.

Successful growth of Mycobacterium lepraemurium has been achieved by use of a specialized diffusion chamber technique. The cell-impermeable porous chambers were maintained in animals for periods up to 50 days with and without macrophages and LM cells. A generation time of 6 to 8 days was found for the acid-fast bacilli in chambers containing macrophages when maintained in the mouse.

Stabilities of dried suspensions of influenza virus sealed in a vacuum or under different gases.

Suspensions of purified influenza virus, dried to a 1.4% content of residual moisture by sublimation of ice in vacuo, were sealed in a vacuum or under different gases of high purity. The stabilities of the several preparations were determined by an accelerated storage test.

Antiviral activity of carbobenzosy di- and tripeptides on measles virus.

A series of simple carbobenzoxy peptides showed high and consistent antiviral chemotherapeutic activity in cell culture. In general, greatest activity was found against the measles-distemper or herpesvirus groups, or both, but various representatives of the series had quantitatively and qualitatively different antiviral activities. Several of the compounds, showing the highest antimeasles activity, were investigated extensively.

Stability of suspensions of influenza virus dried to different contents of residual moisture by sublimation in vacuo.

After freezing, suspensions of influenza virus were dried by sublimation of water in vacuo to contents of residual moisture of 3.2, 2.1, 1.