The discovery of AZD5597, a potent imidazole pyrimidine amide CDK inhibitor suitable for intravenous dosing

The development of a novel series of imidazole pyrimidine amides as cyclin-dependent kinase (CDK) inhibitors is described. Optimisation of inhibitory potency against multiple CDK's (1, 2 and 9) resulted in imidazole pyrimidine amides with potent in vitro anti-proliferative effects against a range of cancer cell lines. Excellent physiochemical properties and large margins against inhibition of CYP isoforms and the hERG ion channel were achieved by modification of lipophilicity and amine basicity. A candidate with disease model activity in human cancer cell line xenografts and with suitable physiochemical and pharmacokinetic profiles for intravenous (i.v.) dosing was selected for further development as AZD5597.

New classes of antibacterial oxazolidinones with C-5, methylene O-Linked heterocyclic side chains

Exploration of the structure-activity relationships of the traditional C-5 acetamidomethyl side chain of the oxazolidonone antibacterials has yielded new, potent series of compounds of which the first examples, the O-linked iosoxazoles are described in detail, leading to the selection of the pre-clinical candidate AZD2563.

Effects of estradiol and progesterone on the increased synthesis of collagen in atherosclerotic rabbit aortas

The effects of sex hormones on atherosclerosis and collagen synthesis in blood vessels were studied in rabbits fed an atherogenic diet. Ovariectomy without hormone replacement resulted in significantly greater degree of atherosclerosis and collagen synthesis in the aortic arch when compared with the intact state. The administration of estradiol to ovariectomized rabbits resulted in a degree of atherosclerosis and collagen synthesis similar to that of intact rabbits. Ovariectomized rabbits administered progesterone on the other hand resembled the ovariectomized rabbits without hormone replacement. Specific activity of hydroxyproline in individual specimens of the arch correlated strongly with degree of atherosclerosis. An analysis of regional variation demonstrated declining values for collagen synthesis in the caudal direction along the aorta. Collagen synthesis was much higher in the portal vein as compared with the inferior vena cava. Plasma cholesterol values were higher in the ovariectomized rabbits than in the intact rabbits. Tissue deposition of cholesterol paralleled the degree of atherosclerosis.

Diet- and hormone-induced lipid deposition in rat kidney: correlation with systolic blood pressure

The influence of estradiol on deposition of cholesterol in tissues of ovariectomized rats on normal and high lipid diets was studied. Concomitantly the influence of a contraceptive steroid combination was studied in a similar manner in intact rats. It was found that the high lipid diet resulted in increased deposition of cholesterol in aorta, heart, liver and kidney. The presence of either endogenous or exogenous hormones accentuated the deposition of cholesterol in the kidney and resulted in significantly higher systolic blood pressures in these rats. In the rats on a high lipid diet, the concentration of cholesterol in the kidney correlated positively with systolic blood pressure. It is concluded that estrogen and high lipid diet exert a synergistic effect on deposition of cholesterol in kidney. The positive correlation between kidney cholesterol concentration and systolic blood pressure suggests a possible role for kidney lipid deposition in the hypertensive effect of estrogens.

Increased synthesis of aortic collagen and elastin in experimental atherosclerosis. Inhibition by contraceptive steroids

Rabbits were fed an atherogenic or normal control diet for 3 months; half of each group were treated with mestranol--norethynodrel (M--N) and half with cottonseed oil vehicle. At the end of the 3-month period rabbits were killed and aortic collagen and elastin synthesis determine. Collagen and elastin synthesis was increased in aortas of rabbits on an atherogenic diet, but those treated with M--N had a lower rate of collagen synthesis and less deposition of cholesterol in the aorta than those administered cottonseed oil. It is suggested that long-term administration of the contraceptive steroid combination may retard the progression of atherosclerosis through the hormone's effect on vascular connective tissue.

Increased vascular collagen and elastin synthesis in experimental atherosclerosis in the rabbit. Variation in synthesis among major vessels

Collagen and elastin synthesis was determined in 5 regions of the vascular system in rabbits on (a) normal diet and (b) atherogenic diet. Increased connective tissue synthesis was found in 3 different sections of the aorta and in the pulmonary artery of rabbits on the atherogenic diet. The inferior vena cava showed no difference between the two groups. Regional variation in connective tissue synthesis was found in both normal and atherosclerotic animals, the vessels associated with the greatest degree of pulsatile distention in vivo having the greatest synthesis and the inferior vena cava, a low pressure, low distention vessel having the lowest synthesis. It is concluded that the atherogenic process includes stimulation of collagen and elastin synthesis. It is suggested that in addition to the effect of pressure on connective tissue synthesis, pulsatile distention may be a factor in synthesis and may be related to lesion formation.

Pulsatile distention and vascular collagen synthesis in the rabbit

In rabbits, collagen synthesis was studied in five different regions of the vasuclar tree which are subjected to different degrees of pulsatile distention, i.e., cyclic stretching, and mean pressure. The vessels with greatest pulsatile distention had the highest specific activity of hydroxyproline in collagen after incubation with 14C-proline and the inferior vena cava with low pressure and negligible pulsatile distention had the lowest specific activity. The findings suggest a link between mechanical stretching and cellular metabolic function and have significance as to the relationship of pulsatile flow to normal vascular and organ physiology.

Effect of sex hormones on plasma cholesterol in castrated and noncastrated male rats

The administration of estradiol to both castrated and noncastrated male rats was associated with significantly increased plasma cholesterol levels as compared to controls, the estradiol in the noncastrated rats overriding the tendency of testosterone to lower plasma cholesterol.

Effect of sex hormones on blood pressure and vascular connective tissue in castrated and noncastrated male rats

Aortic collagen and elastin were quantitated in three groups of castrated and two groups of noncastrated male rats treated by intramuscular injection for 3 wk with oil, testosterone, or estradiol. The greatest differences were found between the castrated rats receiving testosterone and those receiving estradiol, the estradiol-treated rats having significantly lower total collagen, percent collagen, total elastin, and collagen/elastin (C/E), and higher percent elastin than those rats receiving testosterone. In noncastrated rats, administration of estradiol resulted in significantly lower total collagen, percent collagen, total elastin, and C/E. Systolic blood pressure was highest in rats receiving testerone and lowest in rats receiving estradiol. It is concluded that 1) estradiol in the presence or absence of testosterone decreases total accumulation of vascular connective tissue and alters the proportions of collagen and elastin so that the vessel is more distensible, 2) testosterone has an opposite but less marked effect than estradiol on vascular connective tissue, and 3) estradiol and testosterone alter blood pressure in opposite directions in the male rat.

Mechanics and electrolyte composition of arterial smooth muscle in developing dogs

The effects of age on arterial smooth muscles (SM) mechanics and electrolyte composition were studied during growth and development in six litters of puppies and their mothers from isolated segments of carotid, renal, mesenteric, and iliac arteries. An increase in the maximum wall stress following both norepinephrine (NE) and potassium (K) was found with age at all sites. The ratio of the stress response for K/NE was found to decrease with age. The maximum stress response for both NE and K shifted to lower values of wall strain with age in the same manner that passive stress-strain curves were shifted. The maximum diameter re3 (3 SM activator to SM activator were not significantly altered with age, but they were better maintained at higher transmural pressure in older animals. Chemical analysis indicated "cell" water, Mg, and K contents decreased with age, as did extracellular water, Na, and Cl. Na anhe suggest that changes in SM excitation-contraction coupling occur with age. Passive wall elements appear to interact with the contractile elements in determining wall responses to SM activation.