Homeostatic control of manganese excretion in the neonatal rat

Journal Article · Fri May 01 04:00:00 EDT 1987 · Am. J. Physiol.; (United States)

OSTI ID:6861561

Ballatori, N; Miles, E; Clarkson, T W

Previous studies in neonatal and suckling animals showed that immature animals have a greatly diminished capacity to excrete manganese and therefore were considered to be unable to regulate tissue manganese concentrations. In contrast, the present studies indicate that suckling rats have the capacity to excrete excess manganese at rates nearly comparable to those of adults. Eight- to 10-day-old rats given a tracer dose of /sup 54/MnCl/sub 2/ (essentially carrier free), either via gavage or by intraperitoneal injection showed little elimination of the /sup 54/Mn until the 18-19th day of life, when there was an abrupt increase in the rate of the metal's excretion. However, when manganese was given in doses of 1 and 10 mg/kg, the young animals excreted from 30-70% of the dose in only 4 days, at which time a new rate of excretion was achieved. This enhanced rate of excretion remained constant until the 18-19th day of life, when it was again accelerated. Biliary excretion of manganese, the primary route for the elimination of the metal, was only 30-60% lower in 14-day-old rats compared with adults at doses ranging from tracer to 10 mg /sup 54/Mn/kg. For both the 14-day-old and adult rats, an apparent biliary transport maximum was reached at a dose of 10 mg Mn/kg. These studies indicate that the excretory pathways for manganese are well developed in the neonatal rat. The avid retention of tracer quantities of manganese by the neonate may be a consequence of the scarcity of this essential trace metal in its diet.

• Research Organization: Univ. of Rochester School of Medicine, NY (USA)
• OSTI ID: 6861561
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:5; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

560162* -- Radionuclide Effects
Kinetics
& Toxicology-- Animals
Plants
Microorganisms
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ABSORPTION
ADULTS
AGE DEPENDENCE
AGE GROUPS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BODY
BODY FLUIDS
CHLORIDES
CHLORINE COMPOUNDS
CLEARANCE
DAYS LIVING RADIOISOTOPES
DIET
DIGESTIVE SYSTEM
DOSE-RESPONSE RELATIONSHIPS
ELECTRON CAPTURE RADIOISOTOPES
EXCRETION
GLANDS
HALIDES
HALOGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTESTINAL ABSORPTION
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
LACTATION
LIVER
MAMMALS
MANGANESE 54
MANGANESE CHLORIDES
MANGANESE COMPOUNDS
MANGANESE HALIDES
MANGANESE ISOTOPES
MATERIALS
NEONATES
NUCLEI
ODD-ODD NUCLEI
ORGANS
RADIOISOTOPES
RATS
RODENTS
TRACER TECHNIQUES
TRANSITION ELEMENT COMPOUNDS
UPTAKE
VERTEBRATES