thymosin and Growth-Disorders

Topics: Aging; Embryonic and Fetal Development; Growth Disorders; Humans; Male; Prospective Studies; Spinal Canal; Thymalfasin; Thymosin; Thymus Gland

A high frequency of occurrence of a wasting disease, unthriftiness, and retarded growth was observed in a group of inbred Weimaraner dogs. Affected pups had a small thymus gland, with a marked absence of thymic cortex. A litter of eight pups from a sire and dam that were known to have produced affected offspring was chosen for further study. The pups had normal concentrations of WBC and gamma-globulins and were able to produce antibody in response to Brucella abortus. Two pups in the litter developed a wasting syndrome and responded well to therapy with thymosin fraction 5. One pup that survived the wasting syndrome had a significant (P < 0.05) depression of its lymphocyte blastogenic response to phytohemagglutinin compared with its surviving littermates. Pups from this litter also lacked a normal increase in plasma growth hormone concentration after the injection of clonidine HCl. These pups had concurrent abnormalities of the thymus-dependent immune function and in growth hormone metabolism. The syndrome in these pups has some features in common with the syndrome in the Ames or Snell-Bagg strains of immunodeficient dwarf mice.

Topics: Animals; Dog Diseases; Dogs; Female; Growth Disorders; Growth Hormone; Lymph Nodes; Lymphatic Diseases; Lymphocyte Activation; Male; Thymosin; Thymus Gland

The authors studied the relationship between thymus and growth of long bones in rats in the pre-puberal stage. 150 rats of both sexes were divided in 3 groups: thymectomized, sham-thymectomized and controls. The animals were sacrificed 15 days after surgery, the femurs were collected and measured, in length and breadth. Thymectomized animals have a bone growth significantly lesser in length and breadth when compared to the sham-thymectomized animals. The latter ones also presented a lesser bone growth when compared to the controls. The average body weight was also significantly lesser in thymectomized rats than in controls, the same happening with the shamthymectomized rats. It is suggested that the thymus probably presents some kind of relation with the hypothalamus through a positive feed-back, simulating secretion of substances that would act on the adenohypophysis rising the secretion of growth hormone and the thymus playing a role in maintaining the serum levels of growth hormone and thyroxine necessary for the growth and development of bones.

Topics: Age Factors; Animals; Body Weight; Bone Development; Female; Femur; Growth Disorders; Hypothalamus; Male; Osteogenesis; Pituitary Gland, Anterior; Rats; Reference Values; Sex Factors; Stress, Physiological; Thymectomy; Thymosin; Thymus Gland; Thyroxine