Pituitary stimulation of parathyroid hormone secretion: Evidence in cattle for a parathyroid stimulating hormone

Latman, Neal S.

doi:10.1002/jez.1402120303

Cited by 2 publications

(1 citation statement)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pituitary is a source of many specialized cellular growth factors (17,18). There are still other growth factor(s), yet to be identified, found in conditioned media from cultured pituitary cells (19) and the pituitary appears to contain a factor that can stimulate parathyroid secretion in vitro (20). Hypothalamic extracts are mitogenic for endothelial cells, keratinocytes, mammary melanocytes, and pituitary cells (21).…”

Section: Discussionmentioning

confidence: 99%

Bovine parathyroid cells: cultures maintained for more than 140 population doublings.

Brandi¹,

Fitzpatrick²,

Coon³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Primary cultures of bovine parathyroid cells were developed using Coon's modified Ham's F-12 medium containing low (0.3 mM) concentrations of calcium and supplements of bovine hypothalamic extract, bovine pituitary extract, epidermal growth factor, insulin, transferrin, selenous acid, hydrocortisone, triiodothyronine, retinoic acid, and galactose. These cells were cultured serially on serum-coated dishes for 140 population doublings before signs of senescence were detected. The cells were epithelioid and maintained a high degree of differentiation as evidenced by calcium regulation of both growth and secretion and by prostaglandin E1 stimulation of cAMP formation and hormone release.Short-term studies with dispersed cells or tissue explants in vitro have yielded considerable information about mechanisms controlling secretion ofparathyroid hormone (PTH) (1) but, unlike well-defined cell culture systems, are not suitable for studies of control of parathyroid cell proliferation and differentiation. Hormone-producing parathyroid cells have been maintained as mixed cell types in culture for short periods but have replicated poorly and eventually become overgrown by fibroblasts (2, 3). The major impediment to effective study of parathyroid cell growth has been the lack of methods for long-term growth of these cells. We describe here a system for primary culture and sustained growth (> 140 population doublings) of differentiated bovine parathyroid cells using serum-coated Petri dishes for cell attachment and a complex serum-free medium for growth. Totally serum-free culture is possible using collagen or fibronectin as a coating for the plates. MATERIALS AND METHODSPrimary Cultures. Bovine parathyroid glands were collected on ice immediately after slaughter and brought to the laboratory in buffer A (20 mM Hepes, pH 7.45, in NIH Eagle's medium 2 without bicarbonate)/1 mM Ca2+/1 mM Mg2+ containing 500 units of penicillin, 500 ,ug of streptomycin, and 100 jig of gentamycin per ml. The glands were sterilized by stirring for 1 min in 0.5% Pheno-cen (Central Chemical, Kansas City, KS) in saline. The tissue was trimmed, minced into fragments, and washed twice in 8 mM sodium phosphate/138 mM NaCl, pH 7.2 (phosphate-buffered saline). One gram of tissue was suspended in 10 ml of buffer A containing 500 ,ug of DNase I (Sigma), 15 mg of collagenase type II (Worthington), 10 mg of glucose, 30 mg of bovine serum albumin type IV, 0.3 mM CaCl2, 0.5 mM MgCl2, and 2% heat-inactivated dialyzed chicken serum. Tissue fragments were digested at 37°C in humidified 95% air/5% CO2 for 3 hr, pipetting every 30 min with a plastic serological pipet. The mixture, washed three times with phosphate-buffered saline by alternately centrifuging at 500 x g and dispersing mechanically, was filtered through 60-pim and 15-,um Nitex mesh screens (Tetko, Elmsford, NY). The small groups of cells that passed through the 60-,um but were retained on the 15-,um filter were collected, suspended in complete GSmF12 medium (see below), and distributed into bov...

show abstract

Section: Discussionmentioning

confidence: 99%