Progesterone functions

Has the properties of progesterone and is given orally for treating functional uterine haemorrhage. Norethisterone, 19-norelhisterone, m.p. 20I-206°C is one of the progestational steroids used in the contraceptive pill. 

Steroid Hormones and Neurosteroids. Steroids (qv) can affect neuroendocrine function, stress responses, and behavioral sexual dimorphism (78,79) (see Steroids). Mineralocorticoid, glucocorticoid, androgen, estrogen, and progesterone receptors are localized in the brain and spinal cord. In addition to genomic actions, the neurosteroid can act more acutely to modulate the actions of other receptors or ion channels (80). Pregnenolone [145-13-17, ( ) dehydroepiandosterone [53-43-0] C H2 02 (319) are excitatory neurosteroids found in rat brain, independent of adrenal... 

Although chlorine azide and bromine azide tend to give some dihalogen adducts, these reagents have been used in the presence of alcohol, ester and epoxy functions without interference.In the case of 17a-acetoxy-A -progesterone, a selective addition to the 6,7-double bond is obtained. ... 

Therapeutic Function Progestin Chemical Name 9/3,10a pregna-4,6-diene-3,20-dione Common Name lOo-isopregnenone 6-dehydro-retro-progesterone Structural Formula ... 

Sex steroid receptors are members of the steroid hormone receptor (SHR) family that ligand-dependently regulate functions of the sexual organs. Sex steroid receptors are the androgen receptor [1] (AR), the estrogen receptor a [2] and (3 [3] (ERa, ER 3), and the progesterone receptor [4] (PR). 

Bagchi, M.K., Tsai, S.Y., Tsai, M.J., O Malley, B.W. (1990). Identification of a functional intermediate in receptor activation in progesterone-dependent cell free transcription. Nature 345,547—550. 

Watanuki, H., Yamaguchi, T., and Sakai, M. (2002). Suppression in function of phagocytic cells in common carp Cyprinus carpio L. injected with estradiol, progesterone or 11-ketotestosterone. Comparative Biochemistry and Physiology C—Toxicology and Pharmacology 132, 407 13. 

These observations, while implicating steroids in brain function and behaviour, cannot be taken as a reliable indicator of their actual effect on neuronal function. Nevertheless, some neurosteroids produce CNS depression with a rapid inhibition of neuronal excitability and one progesterone derivative, alphaxalone (3a-hydroxy-5a pregnane-11, 20 dione, see Fig. 13.5) has been used effectively as an intravenous anaesthetic in humans. 

Intracellular steroid receptors, which alter gene expression, exist for corticosteroids, oestrogens and progesterone in the brain, as in the periphery but they cannot account for the relatively rapid depression of CNS function induced by some steroids. This was explained when Harrison and Simmonds (1984) discovered that alphaxalone (the steroid anaesthetic) potentiated the duration of GABA-induced currents at the GABAa receptor in slices of rat cuneate nucleus just like the barbiturates (Fig. 13.6). Of the... 

Grazzini E, Guillon G, Mouillac B, Zingg HH. Inhibition of oxytocin receptor function by direct binding of progesterone. Nature 1998 392 509-512. 

The summary of Pe values for the steroids as a function of stirring rates is found in Table 11 and their correlations with log PC (n-octanol-water) in Figure 20. The transport kinetics of the relatively hydrophilic hydrocortisone and dexa-methasone are controlled by passive diffusion across the cell monolayer. On the other hand, the Pe values of testosterone and progesterone are highly dependent on stirring rate. The results for testosterone are used to obtain the relationships between the effective permeability coefficients of the ABL on the donor and receiver sides and the stirring rate, using the linear expression (see Eq. (69)]... 

A comparison of the transport quality (Fig. 20.11(B)) with the rate of P-gp-ATPase activation (see Fig. 20.9) as a function of the H-bond energy (EUh) shows that compounds inducing a high rate of ATP hydrolysis (e.g., progesterone) can have a low substrate quality , and vice versa (e.g., cyclosporin). 

---