Vitamin D: Metabolism and Function by Dr. Hector F. DeLuca (auth.)

By Dr. Hector F. DeLuca (auth.)

Because ailments of the bone are usually much less acute and not more lifethreatening than dis­ eases of the circulatory procedure, gastrointestinal tract, kidney, liver, and the apprehensive approach, they've got got a disproportionately smaller quantity of cognizance within the scientific international. With the typical expanding lifestyles span of guy due to enhance­ ments in glossy drugs, espe~ially within the pediatric box, the seriousness of many metabolic bone ailments has certainly turn into extra seen. furthermore, different advancements in medication, reminiscent of hemodialysis for the maintenance of renal failure sufferers, have authorised the improvement of different outcomes of diseased kidneys, one in all that's the looks of renal osteodystrophy. eventually, the looks of a number of genetic issues within the zone of metabolic bone disorder has been underscored via the answer of alternative pediatric diseas~s of even more critical outcomes. those rising difficulties all recommend that a lot is still discovered in regards to the sys­ temic regulate of bone, either as a structural organ and as a reservoir for the real parts of calcium and phosphorus so crucial for the help of lifestyles in advanced multicellular organisms of which guy is crucial. As may be verified within the ancient part of this manuscript, the life of the 3 most crucial humoral components regulating bone metabolism and func­ tion at the moment are known.

Show description

Read Online or Download Vitamin D: Metabolism and Function PDF

Similar endocrinology books

Basic Medical Endocrinology, Third Edition

Easy clinical Endocrinology, 3rd variation presents updated assurance of speedily unfolding advances within the figuring out of hormones serious about regulating so much facets of physically capabilities. The dialogue makes a speciality of molecular and mobile features of hormone creation and motion firmly rooted within the context of integrative body structure.

The Local Cardiac Renin-Angiotensin Aldosterone System

Till lately, the renin-angiotensin-aldosterone procedure has been thought of a systemic endocrine hormonal approach completely. it really is referred to now that every element of the renin-angiotensin approach is produced, synthesized and certainly, found in many organisms together with the center and vessels. This quantity provides the latest medical and laboratory reviews of the top physicians and investigators within the box of the neighborhood cardiac renin-angiotensin aldosterone approach.

Dietary Magnesium: New Research

Magnesium is the fourth such a lot considerable mineral within the physique and is key to strong wellbeing and fitness. nearly 50 consistent with cent of overall physique magnesium is located in bone. the opposite part is located predominantly within cells of physique tissues and organs. only one in line with cent of magnesium is located in blood, however the physique works very not easy to maintain blood degrees of magnesium consistent.

Extra info for Vitamin D: Metabolism and Function

Sample text

1976). In addition, it stimulates 1,25-(OH)zD3 production. The 1,25-(OH}zD 3 stimulates intestinal calcium absorption and together with the secreted parathyroid hormone stimulates the transfer of calcium from the bone fluid compartment to the e{'tracellular fluid compartment. These three sources of calcium cause an elevation of plasma calcium concentration, suppressing parathyroid hormone secretion, thereby shutting down the entire calcium mobilizing system. On the other hand, if hypercalcemia is found or resuits, there is a secretion of calcitonin from the C cells of the thyroid which then suppresses mobilization of calcium from bone and probably stimulates excretion of calcium and phosphorus in the kidney (MAIER, 1974).

The production of 24,25-(OH)P3 is stimulated by 1,25-(OH)P3 and by increased ambient calcium concentration in the culture fluid. Furthermore, it is markedly suppressed by small amounts of parathyroid hormone. These tissue culture results again confirm the independent effects of these three agents in regulating 24-hydroxylase. However, they do not provide insight regarding the mechanism nor do they necessarily extend in a reciprocal manner to I-hydroxylase. There is a need for a tissue culture system that is clearly able to produce on a long-term basis 1,25-(OHhD 3 and that is sensitive to the in vivo regulators.

1972b). 1,25-(OH)P3 would then stimulate intestinal calcium absorption. In support of this concept it has been demonstrated that the administration of 1,25-(OHhD3 eliminates the ability of animals to adjust their intestinal calcium absorption in relationship to dietary calcium levels (RIBOVICH and DELucA, Calcium Homeostatic Mechanisms Involving the Vitamin D Endocrine System 33 1975). Furthermore, parathyroidectomy with the subsequent administration of an exogenous but constant source of parathyroid hormone also eliminates the ability of the intestine to adapt to dietary calcium levels (RIBOVICH and DELUCA, 1976).

Download PDF sample

Rated 4.72 of 5 – based on 22 votes