Connective tissue activating peptides (CTAPs) extracted from leukocytes and platelets stimulate glycolysis and synthesis of glycosaminoglycan and DNA in cultured human connective tissue cells. CTAP-III, isolated from fresh or outdated human platelets, is a low molecular weight single-chain protein with an isoelectric point of 8.5 that markedly stimulates DNA synthesis and multiple aspects of glycosaminoglycan and proteoglycan metabolism. This report presents a definitive comparison of CTAP-III prepared by two methods [one designated (A), alternative] with similar platelet proteins described by others, beta-thromboglobulin (beta-TG) and low-affinity platelet factor 4 (LA-PF-4). CTAP-III, CTAP-III(A), LA-PF-4, and beta-TG have common antigenic determinants documented by immunoprecipitation and radioimmunoassay. CTAP-III, CTAP-III(A), and LA-PF-4 are biologically active in that they stimulate DNA and glycosaminoglycan synthesis by human synovial cells; beta-TG is inactive. Carboxyl-terminal digestion gave identical terminal sequences for CTAP-III, CTAP-III(A), and beta-TG. Amino-terminal sequence data indicate that CTAP-III and CTAP-III(A) (also LA-PF-4) are identical and differ from beta-TG only by an additional amino-terminal tetrapeptide (Asn-Leu-Ala-Lys-). The biologically active molecule, CTAP-III, may be proteolytically converted to its inactive degradation product (beta-TG) in the course of platelet aging, platelet storage, release from the platelets, or initiation of biological activity.

Ischemic heart disease (IHD) mortality of Connecticut firemen and policemen is studied for the years 1960-78, using death certificate data. The mortality of these two occupations is expected to be greater than that of other workers. Standardized Mortality Odds Ratios for firemen and policemen are greater than 1.00. Although some increased IHD risk for firemen and policemen is suggested, the exact role of occupational risk factors remains to be determined. (Am J

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In the normal oestrous cycle of the rat, a fluid accumulates in the uterine lumen during proestrus and oestrus. This fluid has an unusually high K+ concentration (Ringler, 1961). The function of the fluid may be important in capacitation of spermatozoa (Austin, 1951) or in sperm transport.In the present study, administration of oestradiol (1\m=.\0 \ g=m\ g/ day for 3 days) to ovariectomized rats resulted in an accumulation of fluid in the uterine lumen similar to that described by Ringler (1961). When the dose of oestradiol was increased to 10 \g=m\g/day for 3 days, the volume of fluid which accumulated increased and the concentration of K+ also increased to a maximum of 40\p=n-\45 mequiv./l. The Na+ concentration decreased concomitantly so that the sum of the concentrations of the two ions remained constant and suggested the presence of an exchange mechanism.An attempt was made to alter the Na+ and K+ concentrations with agents which have been used to alter Na+ and K+ in other body fluids such as cerebrospinal fluid, urine or saliva (Bradbury & Davson, 1965;Domer, 1969;Schneyer, 1970).In ovariectomized, oestrogen-treated (oestradiol, l-0/íg/day for 3 days) rats, triamterene, 25 or 100 mg/kg, acetazolamide, 50 mg/kg, and progesterone, 1-0 mg/day, given once daily for 3 days (concomitant with oestrogen injection) had no effect on Na+ or K+ concentrations of uterine luminal fluid. Amiloride given acutely, 10 mg/kg i.v. or intraluminally to a final concentration of 10~3 mol/1 and ouabain given intraluminally, final concentration 10~3 mol/1, also had no effect on the Na+ or K+ con¬ centrations of the uterine luminal fluid.An in-vitro preparation was developed to study factors involved in the secretion of K+ into luminal fluid. Fluid was removed from the uterine horns of ovariectomized, oestrogen-treated (oestradiol, 1-0/tg/day for 3 days) animals. The lumen was washed with physiological saline and the cervical end of the horn was ligated. A solution of 0-9 % NaCl was placed in the uterine lumen from the ovarian end of the horn which was then ligated. These fluid-filled sacs were suspended in tissue baths at 37°C containing Ringer-Locke's medium and aerated with 95% 02, 5% C02. Various drugs were added to the bathing medium and the Na+ and K+ concentrations in the