Luteotropic hormone

Luteinizing hormone releasing hormone see Releasing hormones Luteolin see Flavones Luteolinidine see Anthocyanins Luteotropic hormone see Prolactin. 

The menstrual cycle is controlled by three protein hormones from the pituitary gland. The follicle-stimulating hormone (FSH) induces the growth of the egg, and the luteinizing hormone (LH) induces its release from the ovaries and the formation of an ovarian tissue called the corpus luteum. The third pituitary hormone (luteotropic hormone, also called luteotropin or prolactin), stimulates the corpus luteum and maintains its function. 

Hormones of the Anterior Lobe of the Hypophysis. Table XVIII in Section 2 shows that the anterior lobe produces six different hormones somatotropin, thyrotropin, corticotropin, luteotropic hormone, follicle-stimulating, and interstitial cell-stimulating hormones. The last three hormones are grouped together under the generic term gonadotropic hormones. 

The luteotropic effect (LTH = luteotropic hormone) stimulates the production of progesterone in the corpora lutea. 

The luteotropic hormone (LTH) is identical with the lactotropic (or mammotropic) hormone, also called prolactin or lactotropin (for effects, see below). The hormone has been purified from sheep hypophyses and found to be a protein with a molecular w eight of 24,000 the amino acid sequence is partially known. 

Lactate dehydrogenase Luteinizing hormone Luteotropic hormone Melanocyte-stimulating hormone Molecular weight... 

Prolactin (PRL) is a hormone secreted by special cells of the adenohypophysis. It stimulates and sustains lactation in postpartum mammals, the mammary glands having been prepared by other hormones, including estrogens, progesterone, growth hormone, corticosteroids, and insulin. It also stimulates formation of milk in the crop sac of birds, such as pigeons and doves (an action formerly used for bioassay), is luteotropic m certain mammals, and has many other... 

The capacity of human placental protein, as well as human growth hormone and ovine prolactin, to evoke a luteotropic response has been demonstrated by the maintenance of the induced decidual response in experimental animals (16,19,26,27). The data in Table 5 illustrate that PPP(H) at 4.0 mg/kg was comparable to 10 lU (approximately 1.5 mg/kg of sheep LtH), but 20 mg/kg of PPP(H) caused about twice as much increase in uterine weight as 50 lU of LtH. The estimated potency of PPP(K) was roughly 30-80 percent that of LtH. The observations of Josimovich, (26) and... 

Kovacic (27) also suggest that placental peptide was less potent than LtH. The luteotropic effects of human placental lactogen could be completely inhibited by preincubation with an antiserum to human growth hormone (26). 

Another characteristic property of the hormone is its luteotropic effect In animal experiments, lactotropin stimulates progesterone production in the corpus luteum. It is not yet known whether lactotropin and LTH are identical in all species. For the regulation of the cycle see Section II. 

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